In Search of Natural Quasicrystals
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Technological Entrepreneurship – a Key to World Peace and Prosperity”
cc MM CoCorrmickmick NorthwesternNorthwestern Engineering Engineering MaterialMaterialss ScienceScience and and EngineeringEngineering The 2014 McCormick Dean’s Seminar Series Dr. Dan Shechtman – Nobel Laureate Israel Institute of Technology Monday, October 20, 2014 4:00pm, McCormick Auditorium (Allen Center) Reception to follow north of McCormick Auditorium in the Allen Center “Technological Entrepreneurship – a Key to World Peace and Prosperity” Most of the countries in the world lack significant natural resources and are characterized by low standard of living with little hope for improvement due to population growth and mismanagement. This is true also for countries that are rich in natural resources, but do not use them wisely. People that live in countries that enjoy high standard of living are industrious and their countries industrial. The basic reason of this division is technological entrepreneurship nourished by free market economy. Technologically entrepreneurial people make the difference. So, is there hope for everybody on the globe to improve their lives? Can technological entrepreneurship be motivated and taught so that generations of determined entrepreneurs will build up thriving economies? The clear answer to both questions is yes, but the process will take time and dedication. It all starts with education in general and scientific- technical education in particular. There is also a way to expedite the process – start with the already educated engineers and scientists. These are the first candidates for entrepreneurial endeavors. They can do it, but need motivation, continuous instruction and encouraging economic environment until they create successful start-ups and serve as role models for others. The name of the game is motivation. -
Thirty-Fourth List of New Mineral Names
MINERALOGICAL MAGAZINE, DECEMBER 1986, VOL. 50, PP. 741-61 Thirty-fourth list of new mineral names E. E. FEJER Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD THE present list contains 181 entries. Of these 148 are Alacranite. V. I. Popova, V. A. Popov, A. Clark, valid species, most of which have been approved by the V. O. Polyakov, and S. E. Borisovskii, 1986. Zap. IMA Commission on New Minerals and Mineral Names, 115, 360. First found at Alacran, Pampa Larga, 17 are misspellings or erroneous transliterations, 9 are Chile by A. H. Clark in 1970 (rejected by IMA names published without IMA approval, 4 are variety because of insufficient data), then in 1980 at the names, 2 are spelling corrections, and one is a name applied to gem material. As in previous lists, contractions caldera of Uzon volcano, Kamchatka, USSR, as are used for the names of frequently cited journals and yellowish orange equant crystals up to 0.5 ram, other publications are abbreviated in italic. sometimes flattened on {100} with {100}, {111}, {ill}, and {110} faces, adamantine to greasy Abhurite. J. J. Matzko, H. T. Evans Jr., M. E. Mrose, lustre, poor {100} cleavage, brittle, H 1 Mono- and P. Aruscavage, 1985. C.M. 23, 233. At a clinic, P2/c, a 9.89(2), b 9.73(2), c 9.13(1) A, depth c.35 m, in an arm of the Red Sea, known as fl 101.84(5) ~ Z = 2; Dobs. 3.43(5), D~alr 3.43; Sharm Abhur, c.30 km north of Jiddah, Saudi reflectances and microhardness given. -
Contents Contents
Contents CHEMISTRY International January-March 2019 Volume 41 No. 1 Introduction The International Year of the Periodic Table 2019 2 by Jan Reedijk and Natalia Tarasova Features IUPAC and the Periodic Table by G.J. Leigh 6 Criteria for New Element Discovery: Providing Assurance 10 in a Field of Allure and Romance by Sigurd Hofmann Looking Backwards and Forwards at the Development 16 of the Periodic Table by Eric Scerri Isotopic Abundances and Atomic Weights: History of IUPAC 21 Commission II.1 in the Service of Chemistry by John R. De Laeter IUPAC Commission II.1 Today by Juris Meija 24 Isotopes Matter by Norman E. Holden, Tyler B. Coplen, and Peter Mahaffy 27 The New SI: The International System of Units is Getting 32 a Makeover by Ian Mills and Roberto Marquardt IUPAC Wire Election of IUPAC Officers and Bureau Members 36 Juris Meija Made the Top 40 Under 40 37 C. Oliver Kappe is Awarded the 2018 IUPAC-ThalesNano Prize 37 for Flow Chemistry OPCW to Further Enhance Contributions to United Nations’ 38 Sustainable Development Goals 1001 Inventions: Journeys from Alchemy to Chemistry 38 Stamps International 39 Project Place Critical evaluation of homogeneous equilibrium and solubility 40 constants of gadolinium in environmental and biological- relevant conditions 23rd UNESCO/IUPAC Postgraduate Course in Polymer Science 40 Guidance for the Compilation, Critical Evaluation and 40 Dissemination of Chemical Data Making an imPACt On the Discovery of New Elements (IUPAC/IUPAP 42 Provisional Report) IUPAC Periodic Table of the Elements and Isotopes -
Aperiodic Mineral Structures
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Infoscience - École polytechnique fédérale de Lausanne EMU Notes in Mineralogy, Vol. 19 (2017), Chapter 5, 213–254 Aperiodic mineral structures L. BINDI1 and G. CHAPUIS2 1 Dipartimento di Scienze della Terra, Universita` di Firenze, Via La Pira 4, I-50121 Firenze, Italy 2 Laboratoire de Cristallographie, E´cole Polytechnique Fe´de´rale de Lausanne, CH-1015 Lausanne, Switzerland The three-dimensional periodic nature of crystalline structures was so strongly anchored in the minds of scientists that the numerous indications that seemed to question this model struggled to acquire the status of validity. The discovery of aperiodic crystals, a generic term including modulated, composite and quasicrystal structures, started in the 1970s with the discovery of incommensurately modulated structures and the presence of satellite reflections surrounding the main reflections in the diffraction patterns. The need to use additional integers to index such diffractograms was soon adopted and theoretical considerations showed that any crystal structure requiring more than three integers to index its diffraction pattern could be described as a periodic object in a higher dimensional space, i.e. superspace, with dimension equal to the number of required integers. The structure observed in physical space is thus a three-dimensional intersection of the structure described as periodic in superspace. Once the symmetry properties of aperiodic crystals were established, the superspace theory was soon adopted in order to describe numerous examples of incommensurate crystal structures from natural and synthetic organic and inorganic compounds even to proteins. Aperiodic crystals thus exhibit perfect atomic structures with long-range order, but without any three-dimensional translational symmetry. -
Nfap Policy Brief » October 2019
NATIONAL FOUNDATION FOR AMERICAN POLICY NFAP POLICY BRIEF» OCTOBER 2019 IMMIGRANTS AND NOBEL PRIZES : 1901- 2019 EXECUTIVE SUMMARY Immigrants have been awarded 38%, or 36 of 95, of the Nobel Prizes won by Americans in Chemistry, Medicine and Physics since 2000.1 In 2019, the U.S. winner of the Nobel Prize in Physics (James Peebles) and one of the two American winners of the Nobel Prize in Chemistry (M. Stanley Whittingham) were immigrants to the United States. This showing by immigrants in 2019 is consistent with recent history and illustrates the contributions of immigrants to America. In 2018, Gérard Mourou, an immigrant from France, won the Nobel Prize in Physics. In 2017, the sole American winner of the Nobel Prize in Chemistry was an immigrant, Joachim Frank, a Columbia University professor born in Germany. Immigrant Rainer Weiss, who was born in Germany and came to the United States as a teenager, was awarded the 2017 Nobel Prize in Physics, sharing it with two other Americans, Kip S. Thorne and Barry C. Barish. In 2016, all 6 American winners of the Nobel Prize in economics and scientific fields were immigrants. Table 1 U.S. Nobel Prize Winners in Chemistry, Medicine and Physics: 2000-2019 Category Immigrant Native-Born Percentage of Immigrant Winners Physics 14 19 42% Chemistry 12 21 36% Medicine 10 19 35% TOTAL 36 59 38% Source: National Foundation for American Policy, Royal Swedish Academy of Sciences, George Mason University Institute for Immigration Research. Between 1901 and 2019, immigrants have been awarded 35%, or 105 of 302, of the Nobel Prizes won by Americans in Chemistry, Medicine and Physics. -
Previously Unknown Quasicrystal Periodic Approximant Found in Space Received: 13 August 2018 Luca Bindi 1, Joyce Pham 2 & Paul J
www.nature.com/scientificreports OPEN Previously unknown quasicrystal periodic approximant found in space Received: 13 August 2018 Luca Bindi 1, Joyce Pham 2 & Paul J. Steinhardt3,4 Accepted: 16 October 2018 We report the discovery of Al Ni Fe , the frst natural known periodic crystalline approximant Published: xx xx xxxx 34 9 2 to decagonite (Al71Ni24Fe5), a natural quasicrystal composed of a periodic stack of planes with quasiperiodic atomic order and ten-fold symmetry. The new mineral has been approved by the International Mineralogical Association (IMA 2018-038) and ofcially named proxidecagonite, which derives from its identity to periodic approximant of decagonite. Both decagonite and proxidecagonite were found in fragments from the Khatyrka meteorite. Proxidecagonite is the frst natural quasicrystal approximant to be found in the Al-Ni-Fe system. Within this system, the decagonal quasicrystal phase has been reported to transform at ~940 °C to Al13(Fe,Ni)4, Al3(Fe,Ni)2 and the liquid phase, and between 800 and 850 °C to Al13(Fe,Ni)4, Al3(Fe,Ni) and Al3(Fe,Ni)2. The fact that proxidecagonite has not been observed in the laboratory before and formed in a meteorite exposed to high pressures and temperatures during impact-induced shocks suggests that it might be a thermodynamically stable compound at high pressure. The most prominent structural motifs are pseudo-pentagonal symmetry subunits, such as pentagonal bipyramids, that share edges and corners with trigonal bipyramids and which maximize shortest Ni–Al over Ni–Ni contacts. 1,2 Te frst decagonal quasicrystalline (QC) phase found in nature, decagonite Al71Ni24Fe5 , was discovered in the Khatyrka meteorite, a CV3 carbonaceous chondrite3–8. -
79Th Annual Meeting of the Meteoritical Society (2016) 6017.Pdf
79th Annual Meeting of the Meteoritical Society (2016) 6017.pdf DISCOVERY OF NEW Al-Cu-Fe MINERALS IN THE KHATYRKA CV3 METEORITE. Chi Ma1,*, Chaney Lin2, Luca Bindi3, Paul J. Steinhardt2. 1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA; 2Department of Physics, Princeton University, Princeton, NJ 08544, USA; 3Dipartimento di Scienze della Terra, Università di Firenze, Via La Pira 4, I-50121 Florence, Italy; *Email: [email protected]. Introduction: During a nanomineralogy investigation of the Khatyrka CV3 carbonaceous chondrite, we have identified two new alloy minerals (AlCu with a Pm-3m CsCl structure and Al3Fe with a C2/m structure) and associ- ated icosahedrite (quasicrystal Al63Cu26Fe11 with a five-fold symmetry) at micron scales in section 126A of USNM 7908. The section belongs to the larger Grain 126, which is one of the fragments recovered from an expedition to the Koryak Mountains in far eastern Russia in 2011 [1] as a result of a search for samples that would provide infor- mation on the origin of the quasicrystal mineral icosahedrite [2,3,4]. The recovered fragments have meteoritic (CV3- like) oxygen isotopic compositions and are identified collectively as coming from the Khatyrka meteorite [5], which formed 4.5 billion years ago during the earliest stages of the solar system. Khatyrka is unique, so far being the only meteorite to host metallic Al component. Field-emission scanning electron microscope with energy-dispersive X-ray spectrometer and electron back- scatter diffraction (EBSD), and electron probe microanalyzer (EPMA) were used to characterize chemical composi- tions and structures of the minerals in section 126A. -
Cosmic History and a Candidate Parent Asteroid for the Quasicrystal-Bearing Meteorite Khatyrka
COSMIC HISTORY AND A CANDIDATE PARENT ASTEROID FOR THE QUASICRYSTAL-BEARING METEORITE KHATYRKA Matthias M. M. Meier1*, Luca Bindi2,3, Philipp R. Heck4, April I. Neander5, Nicole H. Spring6,7, My E. I. Riebe1,8, Colin Maden1, Heinrich Baur1, Paul J. Steinhardt9, Rainer Wieler1 and Henner Busemann1 1Institute of Geochemistry and Petrology, ETH Zurich, Zurich, Switzerland. 2Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy. 3CNR-Istituto di Geoscienze e Georisorse, Sezione di Firenze, Florence, Italy. 4Robert A. Pritzker Center for Meteoritics and Polar Studies, Field Museum of Natural History, Chicago, USA. 5De- partment of Organismal Biology and Anatomy, University of Chicago, Chicago, USA. 6School of Earth and Environ- mental Sciences, University of Manchester, Manchester, UK. 7Department of Earth and Atmospheric Sciences, Uni- versity of Alberta, Edmonton, Canada. 8Current address: Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, USA. 9Department of Physics, and Princeton Center for Theoretical Science, Princeton University, Princeton, USA. *corresponding author: [email protected]; (office phone: +41 44 632 64 53) Submitted to Earth and Planetary Science Letters. Abstract The unique CV-type meteorite Khatyrka is the only natural sample in which “quasicrystals” and associated crystalline Cu,Al-alloys, including khatyrkite and cupalite, have been found. They are suspected to have formed in the early Solar System. To better understand the origin of these ex- otic phases, and the relationship of Khatyrka to other CV chondrites, we have measured He and Ne in six individual, ~40-μm-sized olivine grains from Khatyrka. We find a cosmic-ray exposure age of about 2-4 Ma (if the meteoroid was <3 m in diameter, more if it was larger). -
EXPERIMENTAL IMPACTS of ALUMINUM PROJECTILES INTO QUARTZ SAND: FORMATION 1,2 1,3 of KHATYRKITE (Cual2) and REDUCTION of QUARTZ to SILICON
Bridging the Gap III (2015) 1071.pdf EXPERIMENTAL IMPACTS OF ALUMINUM PROJECTILES INTO QUARTZ SAND: FORMATION 1,2 1,3 OF KHATYRKITE (CuAl2) AND REDUCTION OF QUARTZ TO SILICON. C. Hamann , D. Stöffler , and W. U. Reimold1,3. 1Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, In- validenstraße 43, 10115 Berlin, Germany ([email protected]; dieter.stö[email protected]; [email protected]); 2Institut für Geologische Wissenschaften, Freie Universität Berlin, Malteserstraße 74– 100, 12249 Berlin, Germany, 3Humboldt-Universität zu Berlin, Unter der Linden 6, 10099 Berlin, Germany. Introduction and Rationale: Impact cratering is a melt particles, shock-lithified sand with and without basic geologic process in the solar system, which was distinct shock effects (PDF, diaplectic glass), and frac- predominant over endogenic geologic processes in the tured quartz grains (for details, see the companion early evolution of geologically active planetary bodies. abstract by Wünnemann et al. [10]). Since this study Since most planetary surfaces are highly porous and/or focuses on chemical projectile–target interaction, we composed of non-cohesive materials (e.g., the lunar will only consider impact melt particles that obviously regolith), understanding the influence of pore space show a crust of projectile melt on their top sides. and non-cohesiveness of materials on the impact pro- The bulk compositions of projectile and target were cess is crucial for gaining insights into the evolution of determined with EMPA and XRF, respectively. Impact planetary regoliths. To this end, numerous theoretical melt particles were studied with optical microscopy, and experimental studies have been conducted (e.g., SEM-EDX, and EMPA. -
Design Rules for Discovering 2D Materials from 3D Crystals
Design Rules for Discovering 2D Materials from 3D Crystals by Eleanor Lyons Brightbill Collaborators: Tyler W. Farnsworth, Adam H. Woomer, Patrick C. O'Brien, Kaci L. Kuntz Senior Honors Thesis Chemistry University of North Carolina at Chapel Hill April 7th, 2016 Approved: ___________________________ Dr Scott Warren, Thesis Advisor Dr Wei You, Reader Dr. Todd Austell, Reader Abstract Two-dimensional (2D) materials are championed as potential components for novel technologies due to the extreme change in properties that often accompanies a transition from the bulk to a quantum-confined state. While the incredible properties of existing 2D materials have been investigated for numerous applications, the current library of stable 2D materials is limited to a relatively small number of material systems, and attempts to identify novel 2D materials have found only a small subset of potential 2D material precursors. Here I present a rigorous, yet simple, set of criteria to identify 3D crystals that may be exfoliated into stable 2D sheets and apply these criteria to a database of naturally occurring layered minerals. These design rules harness two fundamental properties of crystals—Mohs hardness and melting point—to enable a rapid and effective approach to identify candidates for exfoliation. It is shown that, in layered systems, Mohs hardness is a predictor of inter-layer (out-of-plane) bond strength while melting point is a measure of intra-layer (in-plane) bond strength. This concept is demonstrated by using liquid exfoliation to produce novel 2D materials from layered minerals that have a Mohs hardness less than 3, with relative success of exfoliation (such as yield and flake size) dependent on melting point. -
Dan Shechtman
University of Haifa The Senate of the University of Haifa, by virtue of the authority vested in it by the constitution of the University and in accordance with the recommendations of the President and the Executive Committee hereby confers upon Dan Shechtman the degree of Doctor of Philosophy, Honoris Causa in recognition of his scientific breakthrough resulting in the birth of a new field in science, a unique accomplishment achieved by few others; his uncompromising belief in the scientific truth of his discovery despite persistent opposition from senior researchers in the scientific community, and the lesson he teaches that loyalty to truth will ultimately defeat critics; his reminding us that science deals first and foremost with findings and that scientists must never distort findings to serve any other interests; for his deep friendship with the University of Haifa and the great honor his excellence has brought to the city of Haifa and the State of Israel. Conferred in Haifa, Israel 13 Sivan 5772/June 3, 2012 Ami Ayalon Prof. Aaron Ben–Ze’ev Prof. David Faraggi Chairman of the Executive Committee President Rector PROFESSOR DAN SHECHTMAN Nobel Laureate in Chemistry for 2011 Prof. Dan Shechtman was born in 1941 in Tel Aviv. He earned a bachelor’s degree in Mechanical Engineering in 1966, a master’s degree in Materials Engineering in 1968 and a Ph.D. in the same field in 1972 – all from the Technion-Israel Institute of Technology. The following three years, he worked in the American Air Force Aerospace Research Laboratories, where he studied the microstructure and physical metallurgy of titanium aluminides. -
Evidence of Cross-Cutting and Redox Reaction in Khatyrka Meteorite
www.nature.com/scientificreports OPEN Evidence of cross-cutting and redox reaction in Khatyrka meteorite reveals metallic-Al minerals formed Received: 5 December 2016 Accepted: 22 March 2017 in outer space Published: xx xx xxxx Chaney Lin1, Lincoln S. Hollister2, Glenn J. MacPherson3, Luca Bindi4,5, Chi Ma6, Christopher L. Andronicos7 & Paul J. Steinhardt1,8 We report on a fragment of the quasicrystal-bearing CV3 carbonaceous chondrite Khatyrka recovered from fine-grained, clay-rich sediments in the Koryak Mountains, Chukotka (Russia). We show higher melting-point silicate glass cross-cutting lower melting-point Al-Cu-Fe alloys, as well as unambiguous evidence of a reduction-oxidation reaction history between Al-Cu-Fe alloys and silicate melt. The redox reactions involve reduction of FeO and SiO2 to Fe and Fe-Si metal, and oxidation of metallic Al to Al2O3, occurring where silicate melt was in contact with Al-Cu-Fe alloys. In the reaction zone, there are metallic Fe and Fe-Si beads, aluminous spinel rinds on the Al-Cu-Fe alloys, and Al2O3 enrichment in the silicate melt surrounding the alloys. From this and other evidence, we demonstrate that Khatyrka must have experienced at least two distinct events: first, an event as early as 4.564 Ga in which the first Al-Cu-Fe alloys formed; and, second, a more recent impact-induced shock in space that led to transformations of and reactions between the alloys and the meteorite matrix. The new evidence firmly establishes that the Al-Cu-Fe alloys (including quasicrystals) formed in outer space in a complex, multi-stage process.