Nobel Prize Winners À La Carte Stages of This Project

Koji Kimoto Director of the Surface Physics and Structure Unit, Advanced Key Technologies Division, Special interview NIMS History of the advancement of the electron microscope as viewed from Japan

Today, the resolution of electron microscopes has reached the sub-atomic level of The Next 50 pm*. How was this accomplished? The key terms are “high voltage” and “aberration correction.” Here, the two scientists in a teacher-student relationship—Nobuo Tanaka, Presi- Nobuo Tanaka dent of The Japanese Society of Microscopy, and Koji Kimoto, a NIMS unit director, Ambition of President of The Japanese Society of Microscopy, who has been working on materials research using a cutting-edge electron micro- Professor Emeritus of Nagoya University scope—will discuss the history of the development of the electron microscope. Microscopists * 1 pm (picometer) is one-trillionth of 1 m. Humankind’s ambition to see more However, there was a problem in realizing an II broke out, the subcommittee no longer had corrected, resolution can be improved by minute details electron microscope; the image of a specimen access to information from Germany. However, shortening the wavelengths of the electrons. With long lineage and formed by electrons couldn’t be magnified the subcommittee continued its own develop- To achieve this, an ultra-high voltage elec- Kimoto: I would like to begin our talk on the using glass lenses. Amid this situation, the Ger- ment activities, and succeeded in the manu- tron microscope was developed in which the subject of the invention of the electron micro- man physicist Hans Busch suggested in 1926 facture of Japan’s first commercial product in wavelengths of electrons were shortened by continued challenges scope. I have noticed that people who see an that magnetic fields generated by running elec- 1941. I was once told by my mentor, late Pro- accelerating the electrons by applying high electron microscope for the first time often look tric current through a donut-shaped coil could fessor Ryoji Uyeda, that when the war ended voltage to them. Atomic resolution was nearly surprised due to the huge differences in size be used to direct electron beams in a way anal- in 1945, he didn’t feel that Japan was behind in achieved as early as around 1990 when I was a and shape between an electron microscope and ogous to the way that glass convex lenses direct the electron microscope science & engineering university student. Only Japanese manufactur- the optical microscopes which they are familiar light in an optical microscope. Then, in 1931, at all, based on the information that started to ers were producing ultra-high voltage electron Wanting to see things in fine detail is with from science classes at school. the German physicist Ernst Ruska successfully come in from abroad again. Japan Electron Op- microscopes at that time, and they were also Tanaka: The optical microscopes commonly created the world’s first electron microscope. tics Laboratory Co. Ltd., a precursor of JEOL exporting the microscopes overseas. one of intellectual desires of human nature. seen in school science classes magnify small Ltd., which is one of the major electron micro- Tanaka: Ultra-high voltage electron micro- samples using glass convex lenses through Early development in Japan scope manufacturers today, was established scopes once dominated around the world, but Out of such desire, humans invented a microscope which the light illuminating the sample travels in 1946. And in 1949, the Japanese Society a limitation was reached in terms of further magnifying things with light. to form enlarged images. The first optical Kimoto: I believe that the development of of Electron Microscopy was launched. I am shortening the wavelengths of electrons by microscope was invented in the 17th-century electron microscopes in Japan began when the currently serving as a president of the society, increasing the acceleration voltage. According But scientists’ ambition was not satisfied there. in the Netherlands. On the other hand, looking subcommittee of the Japan Society for the Pro- and it is one of the older scientific societies in to Einstein’s special theory of relativity, as the into the history of electron microscopes, we motion of Science (JSPS) was founded in 1939. Japan. speed of electrons nears the speed of light, the They stepped into an even more Lilliputian world. ultimately arrive at the 1923 account by the Is that correct? mass of the electrons increases. So, eventually In the course of this pursuit, French physicist Louis de Broglie, who said Tanaka: The news that the first electron mi- Strategy involving high voltage the effort to increase the speed of electrons that electrons are also waves. Before that, croscope was invented in Germany quickly reached a plateau. Due to this situation, the they suceeded in looking at atoms electrons had been considered as particles. reached Japan. Then, based on the idea that Kimoto: Electron microscopes are capable of resolution of ultra-high voltage electron mi- Electron microscope originated from the idea croscopes remained unimproved for a certain using electrons instead of light. Japan should manufacture its own electron mi- achieving atomic-level resolution in theory, but that if electrons are waves, then it must be croscopes, the 37th subcommittee for research their initial resolutions were lower than their period. While looking back on the past endeavors toward feasible to observe magnified images of small on electron microscopes was organized in the potential. samples using electrons in a similar way to how JSPS with Shoji Seto, professor of The Univer- Tanaka: The electrons that pass through the Lineages surrounding electron micro- accomplishing atomic-level vision, an optical microscope works. sity of Tokyo, appointed as a chairman. periphery of a lens contribute to a blurred scopes: Germany and Japan Wavelengths determine resolution. When visible let’s take a glance at what is coming next Kimoto: I also heard that in addition to re- image, as they deviate from the focal point. light, with wavelengths ranging between 380 searchers from universities and research insti- This effect is called a spherical aberration, Kimoto: In the meanwhile, Germany was try- in the world of electron microscopy. and 800 nm (1 nm [nanometer] is one-billionth tutes, engineers from manufacturers joined the which reduces a microscope’s resolution. ing to correct spherical aberrations. This effort of 1 m), is used, the maximum possible resolu- subcommittee. Since the time when the electron microscope was led by Harald Rose, Maximilian Haider tion attained is about 100 nm. In comparison, Tanaka: Some manufacturers such as Hitachi, was invented, this aberration has been a cause and Knut Wolf Urban who won the 2015 when electrons with wavelengths much shorter Ltd., Shimadzu Corp., Tokyo Shibaura Denki of problems. In addition, achieving electrical NIMS Award. You know them very well and than those of visible lights are used, observation (currently Toshiba Corp.) and Yokogawa Elec- stability had been a challenge for many years. you were closely following their research in of atomic-level objects is possible in theory. tric Corp. indeed took part. When World War Kimoto: Even if aberrations are not fully progress. How did they develop the aberration

02 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 03 Special interview History of the advancement of the electron microscope as viewed from Japan

correction technology? Miyake, Kikuchi and Uyeda respectively pur- was difficult to correct aberrations using film. as a committed engineer. When he tested the advancements. In addition, this correction resolution of 50 pm or less. Furthermore, sample I brought, the device wasn’t good technology also reduced the measurement Japan developed its own aberration correc- Tanaka: To start with, you might be wonder- sued study on X-ray diffraction, atomic nuclei Tanaka: It was the early 1990s when various ing why the aberration correction technology and electron microscopy, respectively. There technologies, such as CCD digital cameras enough for my applied research purposes time, for instance, from one hour to one min- tion device, and succeeded in correcting was developed in Germany, not Japan. That is are some other lineages of researchers through capable of in-situ aberration measurements and at that time. After I explained to him the ute. This reduction is important especially fifth-order aberrations. Japan is also working because Germany had a sound academic foun- which many outstanding discoveries were software capable of high-precision control, problems, he brilliantly fixed them in three from the perspective of industrial use such as on the correction of chromatic aberration. At dation that developed with the creation of elec- made. Nevertheless, in the aspect of aberration became fully available. Also, the aberration months. He was an outstanding engineer, a semiconductor production management. present, only two or three countries are able tron microscopes, and was supported by a long correction, the German lineage was superior to measurement method proposed by Friedrich wonderful person and very reliable. In to manufacture transmission electron micro- lineage of researchers. In regard to aberrations, its Japanese counterpart. Zemlin in the late-1970s was helpful. And addition to the performance of the device, our Moving forward from the stage of scopes (TEMs) equipped with aberration cor- German physicist Otto Scherzer began basic finally, applying aberration correction, relationship of trust was also vital. “merely capturing images” rection devices. I believe that Japan definitely research from the 1930s. In 1970s, Rose was Challenge the impossible enhanced resolution of an electron microscope Kimoto: Since Haider gave his all to the de- has caught up with leading countries in this field. an associate professor working at Scherzer’s was achieved for the first time in the world in velopment of the device, he probably would Kimoto: Aberration correction devices have Kimoto: In the future, what kind of electron only have sold the device to people who been becoming popular these days, but the cur- microscope technologies do you think need to laboratory. And Haider was Rose’s student. Tanaka: There are aberrations in optical mi- the mid-1990s by Rose, Haider and Urban with For more than 60 years until mid-1990s when croscopes, too, but that can be cancelled by Urban taking charge of actual observations. could use it properly. I suppose that he decid- rently available commercial products are capable be developed? they succeeded in correcting aberrations, they combining convex lenses with concave lenses. There was another path in the development ed to sell it to you as he knew you well. of correcting only third-order aberrations called Tanaka: It is true that we now have means to continued research through generations under On the other hand, in electron microscopes, of an aberration correction device. Ondrej spherical aberrations, which had been the most observe atoms directly, but in most cases, we an unsatisfactory environment. Unfortunately, Scherzer proved in 1936 that concave lenses do Krivanek of the University of Cambridge, a The benefits brought by aberration serious issue. Since there are higher order aber- are seeing a column of vertically overlapped at- such a long lineage of researchers does not not work properly in an axially symmetric mag- successor of Albert Crewe who invented the correction rations, it is necessary for the development of oms in a crystal. So, one goal would be to make exist in Japan. There were a few researchers in netic field. Later in 1947, Scherzer suggested scanning transmission electron microscope ↙ correction technology to continue. While Japan individual atoms visible three-dimensionally. Japan who created prototypes of fundamental that aberrations can be corrected by combining (STEM), developed a STEM-compatible was left behind in the commercialization of ↙ Also, in addition to capturing atomic images, ↙ parts based on literature review, but the effort non-axially symmetric magnetic fields gener- aberration correction device. He also suc- is no match for the lineage of researchers in ated by multipole lenses consisting of several ceeded in improving the resolution of STEM Germany. magnetic poles. Rose and others aimed to in the end of 1990s. Japan also has a long lineage in electron microscopy Kimoto: I learned that if you go back in history correct aberrations using the proposed method. research, and I am proud of it. to the time before Scherzer’s era, you will find After the theoretical basis of the aber- The reason behind a decision on the Kimoto: Koji Kimoto that the lineage begins with Arnold Sommer- ration correction method was proposed, it took first installation of aberration correc- feld who pioneered quantum mechanics. Japan many years to achieve its practical use. When tion devices to Nagoya University also has a long continuous tradition in different those researchers gave lectures, they often Kimoto: The use of the aberration correction spherical aberration correction devices, do you device dramatically improved the resolution think Japan can compete with other countries aspects of electron microscopy and diffraction spoke of “mission impossible.” Kimoto: Unlike the method of Rose and oth- to the current 50 pm (0.05 nm) or less. This this time? research, and I personally am proud of it. Tanaka: I heard from Haider in person that ers, Japanese researchers were pursuing the value is less than the radius of a hydrogen Two or three countries have launched Tanaka: Roughly speaking, the lineage of the toughest time he underwent during the method of inserting a thin film in a lens and Tanaka: electron diffraction researchers in Japan goes development of an aberration correction device applying voltage to it, as well as the method atom which is 53 pm. In addition to the aberration correlation projects such as the back to Torahiko Terada at the beginning of came around the end of the 1980s, just before to correct aberrations by processing recorded improvement of resolution, the emergence Transmission Electron Aberration-corrected the 1900s. Shoji Nishikawa was his student, the device was successfully developed. He said images. Since an ultra-high voltage electron mi- of the device had expanded the variation of Microscope (TEAM) Project initiated by the and Shizuo Miyake, Seishi Kikuchi and Ryoji that at that time, he thought he may not make croscope gave us fine images, many researchers objects to be observed. For example, the use United States in 2005. Japan, too, has been Uyeda were Nishikawa’s students. Professors it because people around him told him that that appeared to be satisfied with the results and of an ultra-high voltage electron microscope, carrying out two similar projects since 2004 is an impossible task and there was no research thought that it might be unnecessary to acquire which employs high-energy electron beams, and 2006, respectively. In these efforts, JEOL funding available to him. One reason for having the aberration correction device at that time. damages one-atom-thick nanomaterials such created an electron microscope equipped with as graphene and nanotubes. But the use of aberration correction device, which achieved taken so long to realize aberration correction Tanaka: Since I was an applied researcher, was that peripheral technologies could not catch it was meaningless to merely prove that a the aberration correction device has allowed high-resolution observation without destroy- up with his work. method can correct aberrations. Rather, my Spherical aberration ing the samples due to the use of low accel- further advancement of TEM is necessary Kimoto: In order to correct aberrations, it is profession required stable acquisition of clear, correction device (negative spherical through developing the capability to locally necessary to measure the amount of aberration high-resolution images of various materials. eration voltage. This was a great news for aberration) and adjust multipole lenses. However, up until So, I visited Haider more than five times to materials researchers. measure various physical properties. As for the Tanaka: Also, we used to intentionally need to distinguish different types of atoms, the the 1990s, it took a long time to measure decide whether it was really worth equipping Objective aberrations because the general practice at that the aberration correction device. obtain slightly unfocused images as a means lens electron energy loss spectroscopy which you to obtain contrast. Since this operation is no Blurred image due are working on has taken care of the issue. As time was that electron microscopy images were Kimoto: You acquired the device as the first to spherical taken by film cameras and the film needed to person in Japan around 2000. What made you longer necessary with the current technology, aberration the second goal, I would like to see “limbs” of research on interfaces has made significant atoms or bonds between atoms. Some western be developed. During the film processing, the come to that decision? Sample countries have begun putting efforts into the condition of the microscope might change, so it Tanaka: I was deeply impressed by Haider The principle of aberration correction measurement of scattering due to inelastic scat- tering. If Japan doesn’t work on these subjects right away, it will be left behind again. So I Further advancement of TEM is necessary through develop- Improved resolution by the application of an aber- ration correction device would like to send my encouragement to young ing the capability to measure various physical properties. The white dots represent atoms. The conventional TEM is incapable of separating two adjacent at- Japanese researchers including yourself. oms, showing them as a white oval (left). The TEM Kimoto: We will do our best. Nobuo Tanaka equipped with an aberration correction device is capable of separating two adjacent atoms (right). (by Shino Suzuki, PhotonCreate)

04 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 05 Research Article1 Abberation-corrected STEM（TITAN)

correcting aberrations, I could have obtained the hydrogen atom (53 pm). 0.142nm clearer images more quickly. But we didn’t “We don’t use the STEM with the default have such equipment at NIMS at that time, specifications set by the manufacturer. We Observing atoms, although I didn’t want to use that as an make improvements to it and develop our excuse,” says Kimoto. “In addition to the own measurement system control software. improvement made to the STEM, I searched These modifications allow us to enhance the for other ways to address these issues without performance of the STEM beyond the level recognizing elements using aberration correction devices by sim- preset by the manufacturer’s guaranteed spec- ulating and studying quantum-mechanical ifications. Through these efforts, we try to see Koji Kimoto succeeded element-selective imaging at atomic resolution, effects such as the propagation and the scat- things that cannot be seen by others.” in addition to visualizing individual atoms in crystals, tering of electrons by atoms in a crystal.” The image of graphene (beside the title of first in the world. Graphene observed using an Three months after Kimoto’s publication, this article) demonstrates the high perfor- aberration-corrected STEM researchers in the United States published mance of NIMS’ STEM. Graphene consists of a paper in Science documenting their carbon atoms arranged in a hexagonal lattice Koji Kimoto If you look at atoms using an electron the development of materials, it’s important that a combination of this method with STEM success in discerning different elements and is only a single-atom thick. “It is difficult Director of the Surface Physics and Structure Unit, microscope…… to recognize the arrangements of elements. would allow discriminating different types of Advanced Key Technologies Division, by examining individual atoms using both to produce a graphene image as good as this NIMS And for this purpose, it’s necessary to identify elements due to the element-specific spectra. an aberration-corrected STEM and EELS. one. People from the microscope manufac- Electron microscopy enables you to look at the different types of elements by examining But the theory had not yet been realized at the “Their image quality was almost similar to turer even asked us to give a copy to them for atoms. But what exactly do they look like? individual atoms.” level of atomic arrangements.” mine, but their images contained many more use in presentations.” ductors developed in terms of the number of The scanning transmission electron micro- In order to distinguish different elements, pixels, were taken with a wider field of view, Kimoto produced this image using the auto layers they include, and each type has a differ- scope (STEM) forms an image by scanning Visualizing atomic arrangements in it is necessary to measure electron energy and were produced in 30 seconds. It was measurement function of his own software, ent transition temperature to a superconduc- a tightly focused electron beam across the different elements loss for individual atoms. And to accomplish utterly surprising to me, and I realized that which had been developed since the time tive state. The research group succeeded in the sample and using electrons that pass through this, the electron beam must be narrowed to a my method was inadequate for materials when NIMS did not possess an aberration visualization of atomic arrangement in each the sample. The resulting image is monochro- Kimoto has been carrying out research since width of 0.1 nm, which is close to the diam- evaluations as it allowed us to look at only a correction device, and combining 300 images element using the STEM and EELS (Fig. 3). matic and shows rows of white dots represent- 2003, aiming at the discrimination of ele- eter of an atom, before penetrating a single very limited area of a material at a time and it into one. This study related to the relationship between ing atoms (Fig. 1, left). Because we observe ments. He paid attention to the energy that is atom. That is really a challenge. took us one hour to take measurements. But atomic arrangements and physical properties, electrons scatter as they interact with atoms in lost when interaction occurs in the specimen Kimoto began to enhance an existing STEM. the fact that I produced positive results in this Discrimination of lightweight ele- and the information is expected to be useful in the specimen, the positions of atoms show up between the transmitted electrons and the First, he improved the STEM’s mechanical endeavor before anyone else in the world ments become achievable the development of practical materials. as bright dots in the image. An element with a atoms. An atom consists of a nucleus at the and electrical stability by about 10 times to was of great significance.” The group also receives frequent requests to greater atomic number causes the interacting center and surrounding electrons forming prevent the electron beam from missing the The research group including Kimoto ana- analyze lithium (Li) battery-related materials. electron beam to scatter more intensively, shells. The amount of energy lost due to targeted atom. Then, he set up the improved Spatial resolution that matches atomic lyzes not only samples from NIMS but also “Li is a difficult element to analyze because of resulting in a brighter dot in the image. How- interaction between the transmitted electrons STEM in a special vibration-proof experi- radius those from universities, research institutes and its small atomic number,” says Kimoto. But ever, it is very difficult to distinguish elements and the electrons in the atoms’ inner shells mental building. Moreover, he eliminated as private companies in Japan. A bismuth (Bi) the STEM at NIMS is capable of analyzing of individual atoms solely based on mono- is unique for each element. As such, one can much external disturbance—such as change NIMS finally acquired a STEM equipped high-temperature superconductor is one of Li because it is equipped with a device called chromatic images. identify which atom is associated with which in temperature—as possible by cutting and with an aberration correction device at the them. This material was developed in 1988 a monochromator which converts electron “Visualizing atomic arrangements is a re- element by measuring the energy of the pasting insulation material around the STEM. end of 2010 (Fig. 2). To minimize the effect at NIMS, and consists of stack layers of Bi, beams into monochromatic electron beams. markable accomplishment and it is exciting captured interacted electrons. “This method Later, in 2007, he succeeded in visualizing of external noise and vibration on STEM op- strontium (Sr), calcium (Ca) and copper (Cu). The use of this device has greatly increased to look at them,” says Kimoto. “But to use is called electron energy-loss spectroscopy atomic arrangements in different elements eration, the STEM was set up in the basement There are several different types of supercon- the energy resolution from 1 eV (electron the results of electron microscopy analysis for (EELS), and it was proposed in the 1980s for the first time in the world by combining of a building most distant from a major road volt) to 70 meV. As a result, it is now feasible STEM STEM and electron energy on the NIMS campus. In addition, to avoid images to analyze elements with small atomic num- loss spectroscopy, and pub- the impact of floor vibration, the STEM was bers and discern two different elements with lished the study in the scien- set on an active anti-vibration table, and to similar energy levels. tific journal Nature (Fig. 1). prevent rapid change in atmospheric pressure, Kimoto’s ambition never ends as he says, The commentary article in temperature and air flow in the microscope “I also want to study soft materials. For ex- the journal was dominated by room, the door to the room was doubled. ample, I want to look at molecules in amino positive opinions and point- After setting a specimen, the rest of the STEM acids. Most specimens we are analyzing now ing out the significance of operations were remotely conducted from the are crystals consisting of numerous atoms. It Kimoto’s accomplishments. next room with an insulated double paned would be great if we can increase the STEM’s At the same time, limitations window connected to the microscope room. spatial resolution and detection sensitivity. of the experimental device, “Even though the STEM is equipped with an Then, I would like to place a molecule on STEM image Images showing the distribution of Crystal structure different elements such as the fact that it took aberration correction device, it is still neces- graphene and look at it while preserving its one hour to obtain the image, Fig. 1. STEM image of manganese oxide and the identification of different sary to thoroughly eliminate external distur- functions.” elements. were also pointed out. “I bance so that atoms can be observed with high His challenge to observe things no one has In STEM images, while the positions of elements can be identified as white spots, knew that if I had access to precision,” says Kimoto. The current spatial seen before using an electron microscope it is not feasible to distinguish different types of elements (left). With combined use a STEM that was equipped Fig. 3. Images showing the distribution of of STEM and EELS, atomic arrangements in different types of elements can be resolution is 50 pm (0.05 nm), which is nearly different elements in a bismuth will continue on. identified (right). Fig. 2. Aberration-corrected STEM with a device capable of the same as the radius of the smallest atom, high-temperature superconductor. (by Shino Suzuki, PhotonCreate)

06 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 07 Research Article2 Orthogonally-arranged FIB-SEM

because the instrument was basically designed created assuming the size of a specimen being for surface processing. about 0.1 mm, but Hara pointed out that the 6μm 2μm The positioning of the FIB and the SEM size was too small. “There is a wide range A perfect match of was the biggest problem. For the purpose of of steel materials in terms of size, from the simultaneous observation and processing, it nanometer level to the millimeter level. We manufacturer’s new technology is ideal to position the FIB and the SEM so insisted that the FIB-SEM should enable us that their optical axes intersect at about 60°, to observe samples in this size range.” After as this arrangement allows the FIB and the holding discussions and revising the prototype and researchers’ needs SEM to view the same point at the same time. over and over, we finally created a product It all started from one manufacturer came up to Toru Hara, asking for However, due to the slanted placement of the with the capacity to observe samples that are Three-dimensional image re- SEM with respect to the surface of the sam- as large as 4 mm square and 2 mm thick. advice.Hara tells us the story behind the development of an electron constructed by extracting only precipitates from tomographic ple, when tomographic images were produced Hara also did not compromise on his asser- microscope capable of high-precision three-dimensional structure analysis. images of heat-resistant steel in succession while surface processing was tion to create a multipurpose FIB-SEM, repeatedly performed, there were problems saying, “I want to gather many types of such as occurrence of drift among SEM imag- information in one scan.” As a result, the final Toru Hara Chief Researcher, es. “If our purpose is to analyze the sample’s product was made compatible with several Electron Microscopy Group, Electron microscope was just for a sup- of the FIB-SEM, and as such, the SEM was enhance the precision of three-dimensional three-dimensional structure at high precision, detectors such as an energy dispersive X-ray Surface Physics and Structure Unit, Advanced Key Technologies Division, portive function. considered a secondary device supporting the imaging by an FIB-SEM. the best approach is to arrange the FIB and spectrometer capable of identifying element NIMS processing performed by the FIB,” explains “My area of expertise is metal materials the SEM perpendicularly. It seems easy to do, composition in a sample, an electron back- “Actually, FIB-SEMs existed for many years. Hara. including steel. Like many other materials but in fact no one had succeeded in achieving scatter diffraction analyzer capable of iden- asked about the most impressive specimen The key point of the recent development was and like organisms, steel materials have that. And I found that Hitachi High-Tech Sci- tifying crystal orientation, and a scanning he has analyzed, Hara answered, “I have the invention of orthogonally-arranged FIB- Improvements made by the 30° differ- a three-dimensional hierarchical structure. ence knew how to do it.” transmission electron microscope (STEM) analyzed a skull of a chicken embryo, a dental SEM,” says Hara. But to begin with, what is ence Many researchers in this field had been capable of observing the final remaining thin material and an ancient pigment.” In the study FIB-SEM? trying different methods, including FIB-SEM, Matching the manufacturer’s new fragment of sample after a series of sample of the skull, he analyzed from its surface to The instrument consists of two parts: an FIB “Around 2008, I was consulted by an engi- that might work to internally visualize the technology and researchers’ needs slicing. the deeper layers, and observed the bone and an SEM. FIB stands for “focused ion neer at Hitachi High-Tech Science Corpora- three-dimensional structures of materials for The first FIB-SEM product was completed tissue formation process (Fig. 3). beam.” It is used to process the surface of a tion. He said that they had a technology with precise structural studies.” Hara wasted no time taking a sample to in 2011 and was delivered to NIMS (Fig. 2). specimen by scanning a finely focused ion strong potential, and he wondered if I had If you thinly cut the surface of a sample be observed under the FIB-SEM prototype When NIMS researchers observed heat-re- Excellent operators and rich know- beam to sputter atoms from the surface. FIB any good ideas as to what to apply it to,” says using an FIB and observe it using an SEM, Hitachi High-Tech Science created. “It was sistant steel using the product, it captured how are the strengths has been used since around the mid-1980s for Hara, looking back on the conversation. Hara you can obtain a tomographic image at a amazing. I expected that the precision of the the distribution of interfacial precipitates in microfabrication of semiconductor devices. learned that the technology would enable an certain depth. Then, if you repeat this process prototype would be higher than that of the a three-dimensional image (beside the title There are presently almost 10 orthogonally- SEM stands for “scanning electron micro- FIB and an SEM to be positioned at right and reconstruct an image based on the serially conventional FIM-SEMs, but what I actually of this article). “During the development of arranged FIB-SEMs in use in Japan. No scope,” which enables image production and angles (Fig. 1, right). Conventionally, the FIB produced tomographic images obtained using saw was beyond my expectation.” They soon the orthogonally-arranged FIB-SEM, the overseas manufacturer has pursued the observation of the surface roughness by scan- and the SEM were positioned so that their a computer, you can produce a three-dimen- started joint R&D toward commercialization interests of the highly-skilled engineers at the development of similar products. “I am ning a finely focused electron beam across optical axes intersected at about 60° (Fig. 1, sional structure of the sample. However, there of the new FIB-SEM. “The prototype still manufacturer and the needs of the materials pleased that the product, whose develop- the specimen and capturing back-scattered left). After hearing the engineer’s explanation, was also some inconvenience using FIB-SEM needed a lot of improvements. We—materials researchers who were accustomed to using ment I was involved in, is now widely used, electrons, secondary electrons emitted from Hara thought that this technology might help for three-dimensional structure analysis researchers who often use FIB-SEM—made FIB-SEM perfectly matched.” but it’s a little sad knowing that the one we the specimen and other matters. various requests to improve the product, and are using is now the oldest,” says Hara with In the 1990s, needs to observe and process engineers on the manufacturer made the im- From battery materials to biological smile. “Even so, we have excellent FIB- the surface of a sample at the same time, provements according to our requests.” samples to pigments SEM operators at NIMS and have acquired were increasing. In response to these needs, One of their requests concerned the size of considerable technical know-how. So, our the FIB-SEM was developed. “From the be- specimens to be observed. The prototype was Hara receives requests from external re- analytical skill level is superb.” ginning, processing was the primary purpose searchers to analyze a variety of samples us- Going forward, Hara is planning to place ing the orthogonally-arranged FIB-SEM. more emphasis on steel materials research, his Successive milling using an FIB This instrument has high demand for the original profession. “The microstructure of Tilted Orthogonal analysis of battery materials. Electrodes of steel hasn’t yet been identified at all, and there arrangement arrangement rechargeable batteries and fuel cells need to are many other materials I would like to see contain pores through which electrons and in terms of three-dimensional structure,” says ions can travel. In order to understand the size Hara with a twinkle of interest in his eyes. “If and the arrangement of pores, it is ideal to use there are things I want to visualize, I will take Position of Position of the sample the orthogonally-arranged FIB-SEM capa- an approach of developing new devices and the sample Electron beam Electron beam Fig. 2. Orthogonally-arranged FIB-SEM. ble of performing precise three-dimensional techniques in collaboration with manufac- An FIB-SEM operator, Nakamura (right), says, “Analyzing a skull in a chicken embryo structure analysis. turers’ engineers. That said, I hope to keep was memorable. I was able to obtain clean thin pieces of the specimen for STEM.” While most requests to Hara involve material “By obtaining both a three-dimensional image using FIB-SEM and STEM images Embedded bone tissue The length of one side = 25 μm a balance between materials research and from the same specimen, you can performed more detailed analysis. But that can Fig. 3. Observation of a skull in a chicken embryo, samples, observation of biological speci- device development.” Fig. 1. Positioning of the FIB and the SEM in an FIB-SEM. be achieved only by experienced operators,” says Hara. from the surface layer to the deeper section. mens is also carried out sometimes. When (by Shino Suzuki, PhotonCreate)

08 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 09 necessary to increase the resolution in the Research Article Confocal STEM depth direction. But we were beginning to 3 find that it would be difficult to apply the method to produce images using electrons that passed through the specimen, based on both experimental results and theoretical pre- Revolutionary idea of dictions,” explains Hashimoto. “So, we tried to increase resolution in the depth direction “moving a specimen” using a different method called annular dark- field imaging, in which images are produced using scattered electrons in the specimen.” in STEM The research group repeated the process of creating and testing apertures to be used for NIMS invented a new technology enabling high-resolution, three-dimensional annular dark-field imaging. “We greatly im- Masaki Takeguchi Ayako Hashimoto Reconstructing three-dimensional Director, Senior Researcher, Electron Microscopy Group, observation of a specimen’s internal structure. A research group led by Masaki structures of platinum nanoparticles proved our skills and speed in aperture making Transmission Electron Microscopy Station, Surface Physics and Structure Unit, Takeguchi and Ayako Hashimoto played a central role in this accomplishment. on carbon nanostructures as we created many of them,” says Hashimoto Research Network and Facility Services Division, Advanced Key Technologies Division, NIMS NIMS smiling. “As we improved the quality of the aperture, the resolution in the depth direction gradually increased. I really felt the advantage Three-dimensional imaging using At the same time, Argonne National Lab- working on three-dimensional imaging using of the hand-making approach as we were able the vertical direction due to insufficient depth will happen.” STEM oratory in the United States also had been confocal STEM, but their progress was slow. to quickly repeat testing and revision steps.” resolution. However, by the time the project Takeguchi’s group is also developing a new conducting R&D to realize confocal imaging They had come to the conclusion that the was completing at the end of fiscal 2010, the specimen holders. The inside of the electron With their extremely high resolution and due using STEM since several years before Take- employment of a scanning specimen holder Visualization of internal structures depth resolution was increased to the level at microscope is maintained in a vacuum con- to their atomic-level observation capability, guchi began his study. Because the Argonne was critical for successful development of became reality which a single atom was discernable. dition to prevent the emitted electron beam scanning transmission electron microscopy group did not have the technology to move their product. Takeguchi thought that the joint from scattering due to effects from molecules (STEM) is widely used in a range of situations the electron beam along an optical axis, they research would be beneficial for his group as Takeguchi and others finally succeeded in In-situ three-dimensional observation in the atmosphere. However, requests to make including basic research and practical pur- had not succeeded in acquiring the three- well. three-dimensional imaging employing a con- “in-situ observations” are increasing these poses. However, Takeguchi was not satisfied dimensional structures of specimens. At that time, there was no appropriate elec- focal STEM equipped with a scanning speci- In 2011, NIMS acquired an aberration- days. In in-situ observations, materials of in- with the status of the STEM at that time. “In On the other hand, Takeguchi had a brilliant tron microscope equipped with aberration men holder and an annular dark-field imaging corrected electron microscope (Fig. 3), and the terest are observed under simulated real-world scanning transmission electron microscopy, idea. “Instead of moving the electron beam, correctors at NIMS. But it was available at device. They were able to actually observe research group continues studies today with conditions in terms of high temperatures, the a finely focused electron beam scans across I thought perhaps we could move specimens the University of Oxford. “The University of carbon nanocoils made of coil-formed carbon the goal of more clearly observing specimens’ presence of gases, optical illumination and a sample, and an image of the sample is pro- three-dimensionally by the specimen holder. Oxford was viewed as a leading institute in fiber and reconstruct their three-dimensional internal structures. “Actually, our research hit other factors. To meet these demands, the re- duced using the electrons that passed through I named this movable specimen holder a the field of electron microscopy. I thought that structures. a wall when we found that it was difficult to search group is developing a specimen holder the sample. Due to this imaging principle, “scanning specimen holder” and carried out the collaboration between them and us would The image of the carbon nanocoil in Fig. 1 bring the depth resolution to less than 10 nm, enabling in-situ observation under a variety of STEM images are likened to shadow projec- basic experiments while making the holder by be like the formation of a dream team,” says was produced using STEM without aberration even with the aid of the aberration-corrected environments. tion. For example, if you detect a defect in the hand.” Takeguchi. Consequently, a two-year joint correction. To get further increased depth STEM. Only recently, a key technology for Lastly, Takeguchi said, “An electron mi- sample using a STEM image, you cannot tell In 2007, Hashimoto joined Takeguchi’s research project began from fiscal 2009. resolution, the group combined the aberra- further improving depth resolution was devel- croscope is like a living creature. It tells you whether the defect is located in the upper or R&D project. “I was utterly surprised when tion-corrected STEM at the University of oped. We are now aiming to reach the atomic such things as how it is feeling—good or not lower part of the sample. I had been hoping to Dr. Takeguchi asked me to create an aperture. Improving depth resolution using Oxford and the technologies developed by the level resolution of 0.5 nm,” says Takeguchi good, and what it wants from you when it is somehow observe the three-dimensional inter- Up until that time, my thinking was that an scattered electrons Takeguchi’s group. Then, the group observed enthusiastically. Hashimoto continues with operated. Unless you carefully listen to these nal structures of samples using STEM.” electron microscope was a tool to observe a sample of carbon nanostructures with plat- excitement, “In reality, materials consist of voices, you won’t be able to capture good In optical microscopy, three-dimensional a sample and an aperture was a part of a There was another issue to be resolved in inum (Pt) nanoparticles, and reconstructed atoms arranged in a lattice pattern. But what images. Moreover, it gets angry if you fail to imaging had already been realized by means microscope that could be acquired through order to realize three-dimensional imaging. the sample’s three-dimensional structure (the we are seeing using the electron microscope take good images. I would like to continue of a technique called confocal microscopy. By purchase,” says Hashimoto, looking back on “To capture the three-dimensional internal figure beside the title of this article and Fig. currently available are vertically overlap- to capture images of the microscopic world focusing on a specific depth of a specimen, those days. structure of a sample in detail, it was 2). You can see how Pt nanoparticles are ping atoms. If depth resolution increases, we unknown to science using my own ideas and and removing all transmitted light out of the Takeguchi had his reasons for being insis- dispersed in the carbon structures. In these should be able to distinguish individual atoms hand-made devices.” focal position, you can obtain an image of that tent on making microscope-related devices images, Pt nanoparticles looked elongated in that are aligned vertically. I really hope that (by Shino Suzuki, PhotonCreate) focal position alone. After acquiring several by hand. “Making devices ourselves makes sectional images while refocusing on different it easier for us to fix problems and add new depths of the specimen, you can reconstruct functions. This approach may appear to be these images into a three-dimensional struc- time-consuming, but in reality, research pro- Aberrations not Aberrations Fig. 2. Observation of platinum nanoparti- ture using a computer. Since around 2004, gresses more quickly in this way. And above corrected corrected cles on carbon nanostructures. When an aberration-corrected STEM was Takeguchi had carried out full-fledged R&D all, it’s fun to make devices while seeking used, the nanoparticles looked less elongat- in order to realize three-dimensional imaging creative solutions.” ed vertically in the X-Z images than they did when a STEM without aberration correction by applying the principle of confocal micros- In 2008, Takeguchi and Hashimoto’s group was used. The characteristics of the scanning Sample copy to the STEM. successfully developed a scanning specimen specimen holder also include the ability to holder. Soon after that, researchers at the Fig. 1. Reconstructing a three-dimen- capture X-Z cross-sectional images. The figure sional structure of a carbon nanocoil beside the title of this article (P.10) shows a Moving specimens, not the electron University of Oxford in the United Kingdom The three-dimensional structure was three-dimensional structure reconstructed us- Tip of the scanning specimen holder beam inquired if they could jointly carry out reconstructed using 27 tomographic im- ing 15 sectional images taken at an interval of ages taken at an interval of 100 nm by a 25 nm. Blue indicates carbon nanostructures research with the group. They were also Fig. 3. Scanning-specimen-type STEM without aberration correction. while yellow indicates platinum nanoparticles. confocal STEM.

10 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 11 TALKING WITH TALKING WITH THE BIG THREE

Q: The NIMS Award 2015 selection committee That superficially regarded the images are energy of the imaging electrons with such a THE BIG THREE emphasized your contributions to the fitting so well to our simple-minded ball-and- high precision that characteristic energy losses advancement of materials research... stick models trivializes things dramatically. originating from interaction with sample Understanding what we are actually seeing is electrons can be probed and used for elemental Prof. Rose: It is appreciated that the selection one of the great challenges after we are now identification. This is one of the reasons committee acknowledges the advances in able to penetrate with these new optics into the why STEM is so successful today. In STEM materials science that are enabled by the world of atoms. Is an atom really there where the sample is rasterized by a fine electron new corrected electron optics. We consider we see a "dot" in the image? Can we really beam of atomic-scale lateral extension. This it a privilege that we became the first in the trust a contrast-related or a spectroscopic signal permits atom-by-atom elemental analysis. world to successfully develop an electron localized at the atom position? I really would microscope capable of atomic-level imaging like to emphasize at this point the enormous Q: How did your collaboration all start? through the use of aberration correction progress in computer-based understanding technology. Nevertheless we would like to of atomic images in both TEMs and STEMs. Prof. Urban: Having been responsible over offer a nod from our side to the work that had This is the obverse side to the “gold medal” of many years for a large electron microscopy been done in Germany, in England and in the aberration-corrected atomic-resolution electron installation at Stuttgart I was familiar with U.S. between the 1940s and the early '80s. microscopy. Yes, it is true, by the atomic- electron optics and also the challenges of That it was not successful underscores the resolution studies we are now able to contribute electron-optics technology. On the other hand, extraordinary complexity of the problems to be to nano-scale materials science and to the my real “home” was materials science. I had Prof. Knut Wolf Urban Prof. Harald H. Rose Prof. Maximilian Haider solved. It was clearly a premature conclusion improvement of materials for our daily life. done extended experimental work in many when many "experts" believed that this earlier But it is important to realize that this is done modern fields like superconductivity and Born in 1941. After receiving his PhD from Born in 1935. After receiving his PhD from Technical Born in 1950. After receiving his PhD from Technical work had shown aberration correction to be "in tandem" by improved optics and improved quasicrystals, the prominent research topics of University of Stuttgart, conducted research at University of Darmstadt, he conducted his research University of Darmstadt, he conducted his research impossible by principle. Having worked in quantum physical understanding of our images. the 1980s. And I was in the process of building the Max Planck Institute of Metals Research, and at The New York State Department of Health, at the European Molecular Biology Laboratory. the field for decades I always firmly believed up a new electron microscopy and materials served as a professor at University of Erlangen- University of Chicago, University of Darmstadt, He founded Corrected Electron Optical Systems Nuremberg, Tohoku University, etc. Now Julich Lawrence Berkeley National Laboratory, etc. He has (CEOS) GmbH with Joachim Zach in 1996. He is that aberration correction is possible. We Prof. Rose: Yes, being able to look into the research group at Juelich. I was aware of the Aachen Research Alliance Senior (Distinguished) been Senior Guest Professor of University of Ulm now Honorary Professor of Karlsruhe Institute of are grateful to the Volkswagen Foundation atomic dimensions has opened up a new world. urgent need for atomic resolution in materials Professor of Peter Gruenberg Institute (PGI-5), since 2009. Technology, Senior Advisor of CEOS. that at a time where no other funding agency One should not underestimate the changed research, and I was very pleased that Prof. Rose Research Center Juelich worldwide was prepared to invest in the paradigm; a new mindset is now available, and Prof. Haider invited me to join the team. advancement of electron optics trusted us people are thinking "atomic." I understand that and in the universality of our concept for the one of the reasons for our award selection this Prof. Haider: In my case, this was before I correction of both TEM and STEM optics by year was "popularization" of optical aberration founded the company CEOS together with the hexapole based principle, which we then correction for electron microscopes, and of Dr. Joachim Zach in Heidelberg, because I were able to realize between 1991 and 1997. the application as to the new electron optics to knew Prof. Rose since many years and on materials science and other fields. Let me add many occasions at conferences we discussed Realizing the Impossible Prof. Haider: Indeed, it was hard work where that aberration correction has opened up new the possibility to start an aberration-corrector Development of the world’s 1st aberration-corrected electron microscope each of us had a respective role. It started with research opportunities in a number of fields. the theory, then the realization and afterwards One of these is electron-energy spectroscopy. we knew what we were doing, the demonstration of the advantages of Also, to mention recent advances, the and this formed the basis A trio of eminent scientists - Prof. Maximilian Haider, Prof. Harald H.Rose and Prof. Knut Wolf Urban – this development for the materials science electron microscopy of biological materials, of our optimism recognized for their revolutionary work involving high resolution electron microscopy gave speeches community. We had different backgrounds biomolecules and cells which are suffering upon being presented the NIMS Award 2015. but were able to work together at different from electron-radiation damage appreciates stages in setting up an aberration-corrected substantial increases in specimen lifetime under electron microscope with enhanced resolution the electron beam employing lower electron Soon after the invention of the electron microscope by Ernst Ruska in 1931 (the TEM) and by Manfred von Ardenne in 1937 (the and higher contrast. The device also enabled energies and aberration-correction technology. STEM) it became clear that the resolution of these new instruments is limited by the aberrations of the electron lenses. These lenses are not only to at last see the atoms in matter but also to measure very precisely their positions. Prof. Urban: In the past scientists had to be formed by magnetic fields, and there is a fundamental law in physics which prevents correction of these aberrations by conventional If this achievement led to further progress content with looking at structures. Please note means. So the task left by Ruska and von Ardenne to the next generation was nothing less than to overcome a fundamental law of nature. of various research activities, in particular in that a structure is a “collective property” and Although there were some intelligent theoretical ideas and smart attempts to realize these experimentally in Germany, in England and in materials science, then I am really satisfied! not a single-atomic one. Today we measure the U.S., the right way toward the realization of aberration-corrected electron optics had not been found yet by the early 1980s. At about single-atomic lateral coordinates and shifts Prof. Urban: the same time, based on his earlier systematic work, Harald Rose came up with a novel theoretical concept avoiding the problems of all With respect to the application at the extraordinary precision of better than I should like to emphasize that the atomic 1 picometer. This is just one hundredth of the earlier approaches. That he together with Maximilian Haider and Knut Wolf Urban succeeded to realize his ideas experimentally, the world is a special world governed by quantum the diameter of the smallest of all atoms, the three scientists attributed largely to their team concept: a theoretician (Rose), an experimental physicist with outstanding experience in physics. This is often not appreciated when hydrogen atom. This is where the physics electron optics (Haider) and a materials scientist (Urban). This enabled realization of the world's first aberration-corrected transmission people look at the atomically resolved images happens. And in these dimensions modern electron microscope between 1991 and 1997. This was tantamount to breaking the "sound barrier" as to atomic resolution in materials. which today - thanks to aberration-corrected electron optics meets the modern ab-initio optics - are part of our daily life. The common theoretical computation techniques. These two Today more than 500 commercial aberration-corrected instruments are installed world-wide. With few exceptions, independent of saying of "seeing is believing" does in fact are teaming up for state-of-the-art materials whether these are TEMs or STEMs, all employ the double-hexapole corrector principle developed by the three scientists. not apply to the atomic world's microscopy. science. Furthermore we can analyze the

12 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 13 TALKING WITH THE BIG THREE

the basis of our optimism which never left us. microscopy in biology and other radiation- 9 sensitive objects due to the availability Prof. Haider: “Teamwork for an applicable of high-resolution low-voltage electron TEM” might be a good slogan for us! Each of microscopes operating at voltages below the us had to fulfill our own tasks at the various threshold for atom displacement. This is an Nobel Prize winners à la carte stages of this project. My role was more at area I am now focusing on at Ulm University. Written by Akio Etori the mid-term of this development when the Every October, Nobel Prize winners are Title lettering and illustration by theory was clear and the TEM not yet ready Prof. Haider: I'm sure we can look forward to a announced. Last year, all of Japan got Shinsuke Yoshitake for applications. It was sometimes hard work brighter world due to enhanced collaboration excited over the news that three Japa- when it took more time to find out and to between Japan (via NIMS) and the world. nese scientists—Profs. Isamu Akasaki, solve a hidden problem but with the right There are still many goals to be achieved for Hiroshi Amano and Shuji Nakamura— conviction, strong will and the necessary ultra-high resolution electron microscopy received the prize for their accomplish- enthusiasm not to give up - even if the of imaging of all kind of objects. The ments in the creation of blue LEDs. This problems are seemingly unsolvable - it was research of new materials as well as the year, too, Prof. Satoshi Omura won a No- possible to turn this project into a story of understanding of macroscopic properties at bel Prize in Physiology or Medicine and success for us three together. And our 1997 the atomic level requires new approaches Prof. Takaaki Kajita earned a Nobel Prize right conviction, strong will and success in obtaining about 120 picometers of imaging and analytical techniques. in Physics, resulting in Japanese winners the enthusiasm turned resolution with aberration-corrected imaging for two consecutive years. this project into a story of success opened the gate into a whole new world. Prof. Urban: The future of science will see a continuation of its exponential growth due to Exploration of the minute world has Prof. Rose: The Volkswagen Foundation's new insights and an increase in the availability always been a fascination to humankind project. In summer 1989 at a conference funding was a “condition sine qua non” in of new theoretical and experimental tools. We since ancient times. Several contribu- rich Rohrer at the IBM Zürich Research transistor and integrated circuit (IC). The at Salzburg/Austria all three of us met and order that Prof. Haider could acquire the have been able to enrich science by one of tors to the development of microscopes, Laboratory, who developed a scanning inventors of the transistor were honored discussed the possibilities of getting such a necessary equipment and manpower. As the these, a very universal one, atomic-resolution which helped realize such interest, also tunneling microscope (STM). The STM with the Nobel Prize within 10 years after project funded which was at this time the main old Romans noted, not only "Virtute" (being electron microscopy. Science will also see have won Nobel Prizes. was capable of visualizing the surface their research was recognized. However, obstacle. However, with the clear scientific virtuous, hardworking and having the potential) an exponentially growing need for science- Dutch physicist Fritz Zernike invented of a specimen using tunneling current, the inventor of the IC, Jack Kilby, waited justifications and requests by Prof. Urban but also "Fortuna", or to paraphrase Prof. based solutions. All the great challenges the phase contrast microscope, and and discerning objects as small as 0.1 for 42 years before his Nobel Prize re- we could finally convince the Volkswagen Haider, “luck” are essential prerequisites for of our time, health, environment, climate collected a Nobel Prize in Physics. His ångström. Binnig and Rohrer received ception. He invented the IC in 1958 and the prize only four years after the devel- was awarded the prize in 2000, making Foundation to get for this project the requested successful research. If Prof. Haider allows change, energy, and not to forget personal invention enabled people to clearly ob- opment of the STM in 1982. him the last Nobel Prize winner in the financial support. me to continue to speak on his behalf I would and public safety require science-based serve cells, microorganisms and tissues, like to add that the acquisition of the financial solutions to very, very difficult problems. which were previously difficult to see, as I imagine that Dr. Ruska was really pa- 20th century. well as plastics, oils, fibers and other ma- tient for 55 years, waiting until his Nobel In contrast, there also are very fortunate Prof. Rose: We all used Prof. Haider's in-depth means and the formation of a group of Seeing and understanding atoms in condensed terials. The microscope was widely used Prize reception at the age of 80. As you scientists who won a Nobel Prize only a knowhow of electron optical engineering. engineers required for setting up a successful matter from biomolecules to engineering not only in medical science and practice might know, only living people are quali- year after they announced their research On this platform, Prof. Urban brought forth company, CEOS, for production of parts, materials will play a prominent part in these. but also in the industrial sector. fied to receive the prize. accomplishments: Profs. Alex Müller invaluable applications of the aberration- for licensing and for the continuation of the (Interview: C. Pomeroy) In 1931, German engineer Ernst Ruska Speaking of waiting a long time un- and Georg Bednorz at the IBM Zürich corrected TEM by obtaining atom-resolved R&D was another essential key to success. succeeded in the development of a mi- til being awarded with the prize, Prof. Research Laboratory, who were the re- images with a precision of several picometers what we achieved is croscope that employs an electron beam Yoichiro Nambu, who passed away this cipients of the prize in physics in 1987 Prof. Urban: I would like to add that what based on his expertise in the materials instead of light. His accomplishment year, was another person with a similar for their discovery of high-temperature we achieved is nothing less than a change in nothing less than a change sciences field. This was the starting point for enabled people to look at more micro ob- experience. In the 1960s, he developed superconductors. paradigm in the sense of Thomas S. Kuhn. the electron optical industry to develop the in paradigm jects. However, the Nobel Prize was not a basis for the Kobayashi-Maskawa the- Going back to the subject of micro- Nobody is prepared for it, and we have to new generation of TEMs and STEMs with given to him until 1986—55 years after ory which predicted the existence of six scopes, Profs. Harald Rose, Maximil- the all-time record resolution of about 45 understand the hesitation of the funding he developed the microscope! Since the types of quarks.” When he received a ian Haider and Knut Wolf Urban, who pm permitting better than 1 pm precision. agencies to commit themselves (after decades first electron microscope was developed, Nobel Prize, together with Profs. Makoto developed aberration correction tech- of world-wide fruitless attempts) to fund huge technological advancement had Kobayashi and Toshihide Maskawa, in nology for electron microscopes, have "the impossible". Therefore another key to been made. As a result, the electron 2008, Nambu was 87 years of age. been named as Nobel Prize candidates Q: What do you attribute as a specific key our success was that we spared no effort to microscope today enables perceiving I would like to mention one more person several times, and so have many other to your success? convince the materials research community and objects as small as 50 picometers, which who earned a Nobel Prize decades after world-renowned scientists. It is expect- the funding agencies that the project was doable are even smaller than a single atom. his accomplishment was recognized. ed that many interesting episodes, both Prof. Rose: The key was teamwork: we and promising scientifically and economically. Concurrent with Ruska’s Nobel Prize re- While the current age of information tech- joyful and sad, will continue to emerge as a team took a look from the materials ception, two other contributors to the de- nology is supported by the advancement as winners of this world’s most reputable science perspective, applied modern electron velopment of electron microscopes won and popularization of computers, it was prize are announced every year. optical engineering methods and attained the Q: What do you expect for the future of the prize: Profs. Gerd Binnig and Hein- initially driven by the invention of the required mechanical and electronic stability electron microscope and science?

of the new instrument. With all due modesty Akio Etori: Born in 1934. Science journalist. After graduating from College of Arts and Sciences, the University of Tokyo, he please allow me to mention also the new Prof. Rose: In electron microscopy, I expect produced mainly science programs as a television producer and director at Nihon Educational Television (current TV Asahi) and TV Tokyo, after which he became the editor in chief of the science magazine Nikkei Science. Successively he held posts including construction principles presented in my 1981 more advances in actually utilizing it for director of Nikkei Science Inc., executive director of Mita Press Inc., visiting professor of the Research Center for Advanced Science (for STEM) and 1989 (for TEM) papers. We tasks like manipulations at the atomic level. and Technology, the University of Tokyo, and director of the Japan Science Foundation. knew what we were doing, and this formed Moreover, I expect the revival of electron

14 NIMS NOW 2015 No.6 NIMS NOW 2015 No.6 15