Download or read book Study of New Ternary Rare Earth Intermetallic Germanides with Polar Covalent Bonding written by Riccardo Freccero and published by Springer Nature. This book was released on 2020-11-16 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis focuses on the syntheses, structural characterizations and chemical bonding analyses for several ternary R–M–Ge (R = rare earth metal; M = another metal) intermetallics. The challenges in understanding the main interactions governing the chemistry of these compounds, which lead to our inability to predict their formation, structure and properties, are what provided the motivation for this study. In particular, the R2MGe6 (M = Li, Mg, Al, Cu, Zn, Pd, Ag), R4MGe10-x (M = Li, Mg), R2Pd3Ge5, Lu5Pd4Ge8, Lu3Pd4Ge4 and Yb2PdGe3 phases were synthesized and structurally characterized. Much effort was put into the stabilization of metastable phases, employing the innovative metal flux method, and into the accurate structure solution of twinned crystals. Cutting-edge position-space chemical bonding techniques were combined with new methodologies conceived to correctly describe the Ge–M, Ge–La and also La–M polar-covalent interactions for the La2MGe6 (M = Li, Mg, Al, Cu, Zn, Pd, Ag) series. The present results constitute a step forward in our comprehension of ternary germanide chemistry as well as providing a good playground for further investigations.
Download or read book Synthesis Structure Bonding and Physical Properties of Novel Binary and Ternary Rare earth Metal Germanides written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aspects of composition, structure-bonding, and properties, along with the reasons governing the formation of one phase over another all still, quite surprisingly remain an open question concerning intermetallic compounds. This work was therefore inspired by a need to better understand the above-mentioned characteristics for several binary and ternary rare-earth (RE) germanides. The structure and properties discussed herein, report the crystal chemistry and physical properties associated with over 40 new binary and ternary intermetallic compounds synthesized from their respective elements using either classical solid state reactions or by the metal flux growth technique. All contain the Group 14 element Ge along with several of the lanthanide f-block metals (commonly referred to as rare-earths) which represent the majority of the binary compounds while the ternary compounds include the additional combination of select s - and p -block metals and semi-metals - Mg, Ca, In, Sn. Their crystal structures and compositions were determined using a number of techniques including single-crystal and powder X-ray diffraction, electron diffraction and electron microscopy. Along with the structure and bonding, this dissertation devotes a discussion to the physical properties which are exhibited by these compounds as a function of temperature or magnetic field in association with their bulk magnetic susceptibility, electrical resistivity and heat-capacity. The results from these along with certain similarities in their structure and bonding allows for the classification of five families organized based on their chemical formulae which include the following: (1) RE 5-x Mg x Ge 4 (RE = Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y) containing two types of Ge-Ge dimers of which their bonding can be affected by small changes in the overall composition; (2) RE 2 InGe2 (RE = Sm, Gd, Tb, Dy, Ho, and Yb) containing [Ge 2] dimers connected with four-coordinated In atoms which results in planar InGe 2 layers; (3) RE Sn 1+x Ge1-x (RE = Y, Gd, Tb, Dy, Ho, Er, Tm), RE 2 [Sn x Ge 1-x] 5 (RE = Nd, Sm), RE [Sn x Ge 1-x]2 (RE = Gd, Tb), which uniquely contain two group 14 elements Ge and Sn that are found to preferentially occupy specific crystallographic sites - these being infinite zig-zag chains of Germanium and square sheets of Sn; (4) RE 3 Ge 4 (RE = Gd, Tb, Dy, Ho, Er, Tm, and Y) containing fused fragments of two-bonded zig-zag Germanium atoms; (5) RE 3 Ge 5 (RE = Sm, Gd, Tb, Dy) an example of polymorphism with two dimensional and three dimensional anionic sub-networks with different orientations of zig-zag chains of Germanium.
Download or read book Study of the Magnetic and Transport Properties of the New Ternary Rare Earth Intermetallic RCrSb3 R written by Michael L. Leonard and published by . This book was released on 1999 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare Earth Intermetallics written by W.E. Wallace and published by Elsevier. This book was released on 2012-12-02 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare Earth Intermetallics provides an account of the magnetic characteristics of rare earth intermetallics. This book discusses bulk magnetic characteristics, such as temperature dependence of susceptibility, saturation magnetization, nature of the cooperative magnetic phase, low temperature specific heats, and related thermal properties. Other topics include the magnetic interactions, crystal field interaction by the operator equivalent method, and rare earth-nontransition metal systems. The miscellaneous IVA compounds, rare earth substitution, variation in the iron moment, and compounds with 4d and 5d transition metals are also elaborated in this text. This publication is recommended for students and researchers interested in rare earth intermetallics.
Download or read book Structure and Properties of Intermetallic Ternary Rare Earth Compounds written by Frederick Casper and published by . This book was released on 2008 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rare earth Transition metal Intermetallics written by Mi-Kyung Han and published by . This book was released on 2006 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to explore novel rare-earth, transition metal compounds and to investigate their structure and bonding and how these influence their properties. We have focused on the synthesis, characterization and electronic structure investigations, as well as physical properties of ternary rare-earth Fe-rich intermetallics, e.g., LaFe[subscript 13-x]Si[subscript x], and RE[subscript 2-x]Fe4Si[subscript 14-y], etc. The LaFe[subscript 13-x]Si[subscript x], (1.0 [equal to or less than] x [equal to or less than] 5.0) compounds with structures related to the cubic NaZn13−type are an important series of compounds to study for possible efficient magnetic refrigeration. A systematic structural study of the compositional variation in LaFe[subscript 13-x]Si[subscript x], exhibits a structural transformation from the cubic NaZn13−structure type to a tetragonal derivative due to preferential ordering of Fe and Si atoms. Temperature-dependent single crystal X-ray diffraction at various temperatures and electronic structure calculations (both Extended Hückel and TB-LMTO) was performed on the cubic phases to examine the origin of the large magnetic entropy change. The giant magnetocaloric effect of cubic LaFe[subscript 13-x]Si[subscript x] alloys results from coupling between magnetic ordering and structural transformation. In light of the potential superstructures that could be observed for RE[subscript 2-x]Fe4Si[subscript 14-y] as well as possible modifications of semiconducting [Beta]-FeSi2, we report herein a thorough examination of the chemical composition and structure of RE[subscript 2-x]Fe4Si[subscript 14-y] (RE = Y, Gd-Lu) using a combination of electron microscopy and X-ray diffraction, and demonstrate a new superstructure for this class of compound. The structures are built up of rare-earth silicide planes with approximate compositions "RE1.2Si1.9" alternating with [Beta]-FeSi2-derived (hkl)-type slabs. Investigation by transition electron microscopy (TEM) reveals a superstructure in the crystallographic ab-plane. Fe Mössbauer spectra confirm two different iron environments in superstructure. Magnetic susceptibilities suggest weak magnetic coupling between rare-earth elements, and resistance measurements indicate poor metallic behavior with a large residual resistivity at low temperatures, which is consistent with disorder. Electronic structure calculations on model structures identify a pseudogap in the densities of states for specific valence electron counts that helps to provide a useful electron counting scheme for this class of rare-earth/transition metal/main group compound.
Download or read book Electronic and magnetic properties of ternary rare earth intermetallic phases written by Edward Adam Görlich and published by . This book was released on 1997 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts Index written by and published by . This book was released on 1983 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Crystal Structures and Magnetic Properties of Rare Earth Intermetallics written by Andrej Szytula and published by CRC Press. This book was released on 1994-03-08 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare-earth intermetallics, also known as lanthanide elements, play an important role in the study of magnetic materials and the development of semi- and super-conducting materials. This handbook provides an up-to-date compilation of crystallographic, physical, and magnetic data on rare-earth intermetallic compounds. Over 20 different structure types are described in detail with an emphasis on how crystal structure can affect magnetic properties. Theoretical models for magnetic interactions are described as well as the impact of crystal electric fields on transport properties, magneto crystalline anistropy and hyperfine interactions. This book provides materials scientists, engineers and physicists with all the critical information needed to use rare-earth intermetallics effectively in the development of new materials.
Download or read book Crystal Growth of Intermetallics written by Peter Gille and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermetallic compounds are in the focus of solid-state research for a wide range of future applications, e.g. in heterogeneous catalysis, for thermoelectric generators, and basic research of quantum critical effects. A comprehensive overview is given on various crystal growth techniques that are particularly adopted to intermetallic phases. Experienced authors from leading institutes give detailed descriptions of the specific problems in crystal growth of intermetallic compounds and approaches to solve them.
Download or read book Directory of Graduate Research written by American Chemical Society. Committee on Professional Training and published by . This book was released on 2005 with total page 1932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faculties, publications and doctoral theses in departments or divisions of chemistry, chemical engineering, biochemistry and pharmaceutical and/or medicinal chemistry at universities in the United States and Canada.
Download or read book Semiconducting Silicides written by Victor E. Borisenko and published by Springer Science & Business Media. This book was released on 2013-03-07 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive presentation and analysis of properties and methods of formation of semiconducting silicides. Fundamental electronic, optical and transport properties of the silicides collected from recent publications will help readers choose their application in new generations of solid-state devices. A comprehensive presentation of thermodynamic and kinetic data is given in combination with their technical application, as is information on corresponding thin-film or bulk crystal formation techniques.
Download or read book Ultra High Temperature Materials II written by Igor L. Shabalin and published by Springer. This book was released on 2019-04-24 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: This exhaustive work in three volumes and over 1300 pages provides a thorough treatment of ultra-high temperature materials with melting points over 2500 °C. The first volume focuses on Carbon and Refractory Metals, whilst the second and third are dedicated solely to Refractory compounds and the third to Refractory Alloys and Composites respectively. Topics included are physical (crystallographic, thermodynamic, thermo physical, electrical, optical, physico-mechanical, nuclear) and chemical (solid-state diffusion, interaction with chemical elements and compounds, interaction with gases, vapours and aqueous solutions) properties of the individual physico-chemical phases of carbon (graphite/graphene), refractory metals (W, Re, Os, Ta, Mo, Nb, Ir) and compounds (oxides, nitrides, carbides, borides, silicides) with melting points in this range. It will be of interest to researchers, engineers, postgraduate, graduate and undergraduate students alike. The reader is provided with the full qualitative and quantitative assessment for the materials, which could be applied in various engineering devices and environmental conditions at ultra-high temperatures, on the basis of the latest updates in the field of physics, chemistry, materials science and engineering.
Download or read book Chemistry Structure and Bonding of Zintl Phases and Ions written by Susan Mary Kauzlarich and published by VCH Publishers. This book was released on 1996 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven chapters report current research into the phases and ions of a class of compounds that are electronically positioned between the intermetallic compounds and insulating valence compounds. They cover structure and bonding at the Zintl border, structural patterns of homo- and hetero-nuclear anions and related intermetallic compounds and concepts for interpreting them, the early p-block elements, polyanions in liquid ionic alloys, molecular transition metal complexes, transition metal compounds, and synthesizing and characterizing intermetallic materials using Zintl phases as precursors. An introduction surveys the life and work of German chemist Eduard Zintl (1898-1941). Annotation copyright by Book News, Inc., Portland, OR
Download or read book Solids and Surfaces written by Roald Hoffmann and published by John Wiley & Sons. This book was released on 2021-01-29 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses einzigartige Buch läßt Chemie und Physik im festen Zustand und auf Oberflächen 'zusammentreffen'. In einer lebhaften und anschaulichen Weise bringt es Chemikern die Sprache bei, mit der sie die Elektronenstruktur ausgedehnter Systeme verstehen lernen können. Gleichzeitig zeigt es, wie auch von Seiten der Chemie Modelle über den festen Zustand sowie über Bindungen und Reaktivität von Oberflächen erstellt werden können. Das Buch bedient sich zunächst der Sprache von Kristallorbitalen, Bandstrukturen und Zustandsdichten. Danach stellt es die Werkzeuge bereit, mit denen der Leser weg von den stark delokalisierten Orbitalen des Festkörpers gelangt, darunter der Zerfall von Zustandsdichten und die Population von Kristallorbital-Overlaps. Mit diesen Werkzeugen schafft es der Autor, detaillierte quantenmechanische Berechnungen mit der chemischen Betrachtungsweise mit Grenzorbitalen zu verknüpfen. Die beschriebenen Anwendungen umfassen eine allgemeine Vorstellung der Chemisorption, Bindungsbildung und -zerfall im festen Zustand, Bindungen im Metall, die Elektronenstruktur ausgewählter leitender und supraleitender Verbindungen sowie die für die Deformation ausgedehnter Systeme verantwortlichen Kräfte.
Download or read book Chemical Vapor Transport Reactions written by Michael Binnewies and published by Walter de Gruyter. This book was released on 2012-08-31 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive handbook covers the diverse aspects of chemical vapor transport reactions from basic research to important practical applications. The book begins with an overview of models for chemical vapor transport reactions and then proceeds to treat the specific chemical transport reactions for the elements, halides, oxides, sulfides, selenides, tellurides, pnictides, among others. Aspects of transport from intermetallic phases, the stability of gas particles, thermodynamic data, modeling software and laboratory techniques are also covered. Selected experiments using chemical vapor transport reactions round out the work, making this book a useful reference for researchers and instructors in solid state and inorganic chemistry.
