L. Arulmurugan, M. Ilangkumaran " Experimental Study on Graphene/Transition Metal Chalcogenide Based Energy Storage and Conversion
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Lanthanides & Actinides Notes
- 1 - LANTHANIDES & ACTINIDES NOTES General Background Mnemonics Lanthanides Lanthanide Chemistry Presents No Problems Since Everyone Goes To Doctor Heyes' Excruciatingly Thorough Yearly Lectures La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Actinides Although Theorists Prefer Unusual New Proofs Able Chemists Believe Careful Experiments Find More New Laws Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Principal Characteristics of the Rare Earth Elements 1. Occur together in nature, in minerals, e.g. monazite (a mixed rare earth phosphate). 2. Very similar chemical properties. Found combined with non-metals largely in the 3+ oxidation state, with little tendency to variable valence. 3. Small difference in solubility / complex formation etc. of M3+ are due to size effects. Traversing the series r(M3+) steadily decreases – the lanthanide contraction. Difficult to separate and differentiate, e.g. in 1911 James performed 15000 recrystallisations to get pure Tm(BrO3)3! f-Orbitals The Effective Electron Potential: • Large angular momentum for an f-orbital (l = 3). • Large centrifugal potential tends to keep the electron away from the nucleus. o Aufbau order. • Increased Z increases Coulombic attraction to a larger extent for smaller n due to a proportionately greater change in Zeff. o Reasserts Hydrogenic order. This can be viewed empirically as due to differing penetration effects. Radial Wavefunctions Pn,l2 for 4f, 5d, 6s in Ce 4f orbitals (and the atoms in general) steadily contract across the lanthanide series. Effective electron potential for the excited states of Ba {[Xe] 6s 4f} & La {[Xe] 6s 5d 4f} show a sudden change in the broadness & depth of the 4f "inner well". -
Why Do Transition Metals Have Similar Properties
Why Do Transition Metals Have Similar Properties Saturnalian Haydon never reek so round-the-clock or spruik any explanations in-flight. Cerebrovascular Elisha parries his weasands delaminating disproportionably. Dan divulgate her ohm ought, randy and grouchy. Based on the coinage metals do have low electronegativity The similar properties do transition have similar. However, the trends in these values show the usual discontinuity half way along the series. This chapter on contact, why do transition have similar properties, why does it has both of! What is the major use today cadmium also extend across the oxidizing agent in the row of exceptions to accept varying numbers exhibit so that have similar. Oh, sorry I apologize on that. The more highly charged the ion, the more electrons you have to remove and the more ionisation energy you will have to provide. Transition metals in everything from hand is more rapidly when you would you typically, why do transition have similar properties identified in ionisation energy as inner electrons can be reduced, including superconducting magnets. Here is a result, why transition metals are heated, as is still others, can ask that attack dcp molecules. Density and malleable, why do transition metals have similar properties because cobalt atom of energy for you can be determined by consuming concentrated sulfuric acid with pyrolusite. Make sure to remember your password. It has the symbol Rh. We expect to the new york: he devised the needs no difference between two electrons go now what do transition have similar properties. Also, we do not collect or ask for personally identifiable information on any of our sites. -
The Place of Zinc, Cadmium, and Mercury in the Periodic Table
Information • Textbooks • Media • Resources The Place of Zinc, Cadmium, and Mercury in the Periodic Table William B. Jensen Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172; [email protected] One of the few facts that I can remember from my un- a quarter of the more recent introductory inorganic texts. In dergraduate inorganic course was my instructor’s insistence all cases, the Zn group was incorrectly labeled as being a mem- that zinc, cadmium, and mercury should be classified as main- ber of the d block or transition block. Those introductory block elements rather than as transition-block or d-block el- inorganic texts that presented some sort of systematic survey ements. Though I have always assumed that the evidence for of descriptive chemistry usually contradicted this assignment this statement was unambiguous, I have also noticed the ap- in their later discussions of the chemistry of these elements. pearance over the last decade of an increasing number of gen- On the other hand, the surveys of descriptive chemistry found eral chemistry texts, inorganic texts, and advanced inorganic in most of the general chemistry texts were so superficial that monographs that either explicitly or implicitly contradict this the existence of this inconsistency seldom became explicit. assignment. The inorganic textbook by Cotton and In light of these trends, I thought it might be of interest Wilkinson, which has served as the American standard for to summarize the evidence relating to the proper placement nearly 40 years, has always been firm in its treatment of the of the Zn group within the periodic table. -
Largest Mixed Transition Metal/Actinide Cluster: a Bimetallic Mn/Th Complex with A
Inorg. Chem. 2006, 45, 2364−2366 Largest Mixed Transition Metal/Actinide Cluster: A Bimetallic Mn/Th 18+ Complex with a [Mn10Th6O22(OH)2] Core Abhudaya Mishra, Khalil A. Abboud, and George Christou* Department of Chemistry, UniVersity of Florida, GainesVille, Florida 32611-7200 Received December 6, 2005 A high-nuclearity mixed transition metal/actinide complex has been well-characterized transition metal/actinide complexes, among III - - prepared from the reaction of a Mn 4 complex with Th(NO3)4 in which are the dinuclear metal metal bonded M An orga- ) ) 6a MeCN/MeOH. The complex [Th6Mn10O22(OH)2(O2CPh)16(NO3)2- nometallic complexes (M Fe, Ru and An Th, U) and the family of linear trimetallic M IIUIV (M ) Co, Ni, Cu, (H2O)8] is the largest such complex to date and the first Th/Mn 2 6b species. It is rich in oxide groups, which stabilize all of the metals Zn) complexes containing a hexadentate Schiff base. in the high ThIV and MnIV oxidation levels. Magnetic characterization However, only one of these contains Mn, trinuclear [MnU O L (py) ](L- ) 1,7-diphenyl-1,3,5,7-heptanetetro- establishes that the complex has an S ) 3 ground-state spin value. 2 2 2 4 nato).7 Although Th is used in a wide array of products and processes, the cluster chemistry of Th is poorly developed compared to transition metals: Currently, there - 8a We have had a longstanding interest in the development are metal organic frameworks and organically templated 8b of manganese carboxylate cluster chemistry, mainly because Th complexes known, and the largest molecular Th 9 of its relevance to a variety of areas, including bioinorganic complex is Th6. -
Naming Transition Metal Compounds 2015 Filled In.Notebook January 08, 2016
Naming Transition Metal Compounds 2015 Filled In.notebook January 08, 2016 DO NOW Name the following: 1. CaBr2 2. K2CO3 Write formulas for the following: 3. Nickel (I) Oxide 4. Strontium Sulfate Jan 2312:32 PM NAMING COMPOUNDS WITH TRANSITION METALS Aim: To name compounds with multiple oxidation state metals using roman numerals. Jan 2312:44 PM 1 Naming Transition Metal Compounds 2015 Filled In.notebook January 08, 2016 Iron Oxide Iron Oxide Fe+2 O2 Fe+3 O2 Fe+3 O2 O2 FeO Fe2O3 Iron (II) Oxide Iron (III) Oxide Which formula is correct? BOTH. The name needs a roman numeral with the metal in order to determine which cation is present. Compounds containing metals with multiple oxidation states must have a roman numeral to indicate which cation is present. Jan 2312:44 PM Naming Compounds with Multiple oxidation state metals 1. List all parent ions present. AuCl3 Determine the charge and quantity Au+3 Cl of the anion FIRST. Cl Cl 2. Use the anion charges and the (+3) (3) neutrality rule to determine which metal cation is present. Au must have a +3 charge to make the 3. Name the compound and include compound neutral. a roman numeral representing the charge number of the metal Gold (III) Chloride cation. Jan 2312:44 PM 2 Naming Transition Metal Compounds 2015 Filled In.notebook January 08, 2016 List of Roman Numerals 1 – I 2 – II 3 – III 4 – IV 5 – V 6 – VI 7 – VII Jan 2312:44 PM Naming Compounds with Multiple oxidation state metals 1. -
Conductive-Bridging Random Access Memory
Jana et al. Nanoscale Research Letters (2015) 10:188 DOI 10.1186/s11671-015-0880-9 NANO REVIEW Open Access Conductive-bridging random access memory: challenges and opportunity for 3D architecture Debanjan Jana1, Sourav Roy1, Rajeswar Panja1, Mrinmoy Dutta1, Sheikh Ziaur Rahaman1, Rajat Mahapatra1,2 and Siddheswar Maikap1* Abstract The performances of conductive-bridging random access memory (CBRAM) have been reviewed for different switching materials such as chalcogenides, oxides, and bilayers in different structures. The structure consists of an inert electrode and one oxidized electrode of copper (Cu) or silver (Ag). The switching mechanism is the formation/dissolution of a metallic filament in the switching materials under external bias. However, the growth dynamics of the metallic filament in different switching materials are still debated. All CBRAM devices are switching under an operation current of 0.1 μAto 1mA,andanoperationvoltageof±2Visalsoneeded.Thedevice can reach a low current of 5 pA; however, current compliance-dependent reliability is a challenging issue. Although a chalcogenide-based material has opportunity to have better endurance as compared to an oxide-based material, data retention and integration with the complementary metal-oxide-semiconductor (CMOS) process are also issues. Devices with bilayer switching materials show better resistive switching characteristics as compared to those with a single switching layer, especially a program/erase endurance of >105 cycles with a high speed of few nanoseconds. Multi-level cell operation is possible, but the stability of the high resistance state is also an important reliability concern. These devices show a good data retention of >105 s at >85°C. However, more study is needed to achieve a 10-year guarantee of data retention for non-volatile memory application. -
UCLA Electronic Theses and Dissertations
UCLA UCLA Electronic Theses and Dissertations Title Electrochemical Performance of Titanium Disulfide and Molybdenum Disulfide Nanoplatelets Permalink https://escholarship.org/uc/item/73h6h1z6 Author Siordia, Andrew F. Publication Date 2016 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA Los Angeles Electrochemical Performance of Titanium Disulfide and Molybdenum Disulfide Nanoplatelets A thesis submitted in partial satisfaction of the requirements of the degree Master of Science in Materials Science and Engineering by Andrew Francisco Siordia 2016 ABSTRACT OF THESIS Electrochemical Performance of Titanium Disulfide and Molybdenum Disulfide Nanoplatelets by Andrew Francisco Siordia Master of Science in Materials Science and Engineering University of California, Los Angeles, 2016 Professor Bruce S. Dunn, Chair Single layer crystalline materials, often termed two-dimension (2D) materials, have quickly become a popular topic of research interest due to their extraordinary properties. The intrinsic electrical, mechanical, and optical properties of graphene were found to be remarkably distinct from graphite, its bulk counterpart. In conjunction with newfound processing techniques, there is renewed interest in elucidating the structure-property relationships of other 2D materials ii like the transition metal dichalcogenides (TMDCs). The energy storage capability of 2D nanoplatelets of TiS2 and MoS2 are studied here providing a contrast with investigations of corresponding bulk materials in the early 1970s. TiS2 was synthesized into nanoplatelets using a hot injection route which provided a capacity of ~143mAhg-1 from thin film electrodes as determined by cyclic voltammetry measurements. Phase identification using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy to complement the electrochemical performance and impurity identification is presented. -
Growth of Metal Chalcogenide Nanomaterials and Their Characterizations Yichao Zou Bachelor of Engineering
Growth of Metal Chalcogenide Nanomaterials and Their Characterizations Yichao Zou Bachelor of Engineering A thesis submitted for the degree of Doctor of Philosophy at The University of Queensland in 2016 School of Mechanical and Mining Engineering Abstract Metal chalcogenides, such as IV-VI and V-VI compounds (SnTe, Bi2Te3, Bi2Se3), are ideal candidates for applications in thermoelectricity and topological (crystalline) insulators. This PhD thesis focuses on the controllable synthesis of metal chalcogenide nanostructures via chemical vapour deposition method (CVD), and on the understanding of the crystal structure, growth mechanism, and structure-property correlation in the as-grown nanomaterials. IV-VI and V-VI compounds have attracted extensive research interest because of their excellent thermoelectric properties and exotic physical properties. Nevertheless, there still exist unresolved issues that prevent the further applications of IV-VI and V-VI nanomaterials by rational design, including (1) it is still difficult to grow these nanomaterials with controllable morphology and (2) crystal structure; (3) limited investigations of their growth mechanisms; (4) limited study on structure-property relationships in the nanostructures. Therefore, in this thesis, the controllable growth technique, growth mechanism and structure-property relation in IV-VI and V-VI based nanostructures are explored. The objective is achieved in the following steps: Realizing the morphological control of the nanostructures. (i) By catalyst engineering in Au-catalysed CVD. For SnTe nanostructures, catalyst composition was found to be a key factor controlling the morphology. AuSn catalysts induce growth of triangular SnTe nanoplates, whereas Au5Sn catalysts result in <010> SnTe NWs. For Bi2Se3 nanostructures, catalyst-nanostructure interface was found to have an impact on their growth directions. -
Crystallization Kinetics of Chalcogenide Glasses
2 Crystallization Kinetics of Chalcogenide Glasses Abhay Kumar Singh Department of Physics, Banaras Hindu University, Varanasi, India 1. Introduction 1.1 Background of chalcogenides Chalcogenide glasses are disordered non crystalline materials which have pronounced tendency their atoms to link together to form link chain. Chalcogenide glasses can be obtained by mixing the chalcogen elements, viz, S, Se and Te with elements of the periodic table such as Ga, In, Si, Ge, Sn, As, Sb and Bi, Ag, Cd, Zn etc. In these glasses, short-range inter-atomic forces are predominantly covalent: strong in magnitude and highly directional, whereas weak van der Waals' forces contribute significantly to the medium-range order. The atomic bonding structure is, in general more rigid than that of organic polymers and more flexible than that of oxide glasses. Accordingly, the glass-transition temperatures and elastic properties lay in between those of these materials. Some metallic element containing chalcogenide glasses behave as (super) ionic conductors. These glasses also behave as semiconductors or, more strictly, they are a kind of amorphous semi-conductors with band gap energies of 1±3eV (Fritzsche, 1971). Commonly, chalcogenide glasses have much lower mechanical strength and thermal stability as compared to existing oxide glasses, but they have higher thermal expansion, refractive index, larger range of infrared transparency and higher order of optical non-linearity. It is difficult to define with accuracy when mankind first fabricated its own glass but sources demonstrate that it discovered 10,000 years back in time. It is also difficult to point in time, when the field of chalcogenide glasses started. -
United States Patent to 4,009,052 Whittingham 45 Feb
United States Patent to 4,009,052 Whittingham 45 Feb. 22, 1977 54 CHALCOGENIDE BATTERY the anode-active material a metal selected from the group consisting of Group la metals, Group Ib metals, (75. Inventor: M. Stanley Whittingham, Fanwood, Group IIa metals, Group IIb metals, Group IIIa metals N.J. and Group IVa metals (lithium is preferred), the cath 73) Assignee: Exxon Research and Engineering ode contains as the cathode-active material a chalco Company, Linden, N.J. genide of the formula MZ wherein M is an element selected from the group consisting of titanium, zirco 22 Filed: Apr. 5, 1976 nium, hafnium, niobium, tantalum and vanadium (tita nium is preferred); Z is an element selected from the (21 Appl. No.: 673,696 group consisting of sulfur, selenium and tellurium, and x is a numerical value between about 1.8 and about 2. 1, Related U.S. Application Data and the electrolyte is one which does not chemically 63 Continuation-in-part of Ser. No. 552,599, Feb. 24, react with the anode or the cathode and which will 1975, abandoned, which is a continuation-in-part of permit the migration of ions from said anode-active Ser. No. 396,051, Sept. 10, 1973, abandoned. material to intercalate the cathode-active material. A highly useful battery may be prepared utilizing lithium (52) U.S. Cl. ............................... 429/191; 429/193; as the anode-active material, titanium disulfide as the 429/194; 429/199; 429/218; 429/229 cathode-active material and lithium perchlorate dis (51) Int. Cl’........................................ H01M 35/02 solved in tetrahydrofuran (70%) plus dimethoxyethane. -
Periodic Table 1 Periodic Table
Periodic table 1 Periodic table This article is about the table used in chemistry. For other uses, see Periodic table (disambiguation). The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic numbers (numbers of protons in the nucleus), electron configurations , and recurring chemical properties. Elements are presented in order of increasing atomic number, which is typically listed with the chemical symbol in each box. The standard form of the table consists of a grid of elements laid out in 18 columns and 7 Standard 18-column form of the periodic table. For the color legend, see section Layout, rows, with a double row of elements under the larger table. below that. The table can also be deconstructed into four rectangular blocks: the s-block to the left, the p-block to the right, the d-block in the middle, and the f-block below that. The rows of the table are called periods; the columns are called groups, with some of these having names such as halogens or noble gases. Since, by definition, a periodic table incorporates recurring trends, any such table can be used to derive relationships between the properties of the elements and predict the properties of new, yet to be discovered or synthesized, elements. As a result, a periodic table—whether in the standard form or some other variant—provides a useful framework for analyzing chemical behavior, and such tables are widely used in chemistry and other sciences. Although precursors exist, Dmitri Mendeleev is generally credited with the publication, in 1869, of the first widely recognized periodic table. -
Amorphous Chalcogenide Semiconductors and Related Materials
Amorphous Chalcogenide Semiconductors and Related Materials Keiji Tanaka · Koichi Shimakawa Amorphous Chalcogenide Semiconductors and Related Materials 123 Keiji Tanaka Koichi Shimakawa Graduate School of Engineering Faculty of Engineering Department of Applied Physics Gifu University Hokkaido University Yanaido Kita-ku Gifu 501-1193, Japan Sapporo 060-8628, Japan and [email protected] Nagoya Industrial Science Institute Nagoya 460-0008, Japan [email protected] ISBN 978-1-4419-9509-4 e-ISBN 978-1-4419-9510-0 DOI 10.1007/978-1-4419-9510-0 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2011926594 © Springer Science+Business Media, LLC 2011 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preface Photonic, electronic, and photo-electric applications of non-crystalline1 solids are rapidly growing in recent years. Such growth seems to synchronize with the devel- opment of oxide glass1 fibers and related devices for optical communications, which started near the end of the last century.