Rare Earth Intermetallics
Rare Earth Intermetallics

Author: W.E. Wallace

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 279

ISBN-13: 032315803X

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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.

Handbook on the Physics and Chemistry of Rare Earths
Handbook on the Physics and Chemistry of Rare Earths

Author: Karl A. Gschneidner

Publisher: Elsevier

Published: 2005-03-09

Total Pages: 548

ISBN-13: 9780444515872

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This volume of the Handbook adds five new chapters to the science of rare earths. Two of the chapters deal with intermetallic compounds. An overview of ternary systems containing rare earths, transition metals and indium - Chapter 218 - opens the volume. It is followed by Chapter 219 sorting out relationships between superconductivity and magnetism. The next two chapters are dedicated to complex compounds of rare earths: Chapter 220 describes structural studies using circularly polarized luminescence spectroscopy of lanthanide systems, while Chapter 221 examines rare-earth metal-organic frameworks, also known as coordination polymers. The final Chapter 222 deals with the catalytic activity of rare earths in site-selective hydrolysis of DNA and RNA. Ya. Kalychak, V. Zaremba, R. Pöttgen, M. Lukachuk, and R.-D. Hoffmann review the synthesis conditions, isothermal sections of phase diagrams, crystallography and basic physical properties of ternary intermetallic compounds consisting of the rare-earth metals, transition metals and indium. P. Thalmeier and G. Zwicknagl revisit the last decade of research uncovering some of the mysteries of the superconducting state, especially those related to heavy fermion superconductivity and the co-existence of the superconducting and exotic magnetically ordered states. J. P. Riehl and G. Muller review how the molecular stereochemistry of lanthanide complexes both in pure forms and in mixtures can be probed using circularly polarized luminescence. O. Guillou and C. Daiguebonne assess rare earth-containing metal-organic frameworks, also known as coordination polymers, which hold a potential as working bodies for opto-electronic and magnetic devices, microporous materials for a variety of uses, such as size- and shape-selective separations, catalyst support and hydrogen storage materials. Concluding the volume, M. Komiyama argues that future biotechnology may well rely on the use of rare-earth ions as unique catalysts that can slice DNA and RNA in order to allow their reprogramming, and thus lead to more effective bioengineered processes.

Handbook of Crystal Structures and Magnetic Properties of Rare Earth Intermetallics
Handbook of Crystal Structures and Magnetic Properties of Rare Earth Intermetallics

Author: Andrej Szytula

Publisher: CRC Press

Published: 2020-07-09

Total Pages: 294

ISBN-13: 0429607318

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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.

Transition Metal and Rare Earth Compounds
Transition Metal and Rare Earth Compounds

Author: Hartmut Yersin

Publisher: Springer

Published: 2003-07-01

Total Pages: 198

ISBN-13: 3540444475

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Transition metal and rare earth compounds are investigated intensively because of important questions concerning fundamental research problems. More recently also their enormous potential for the development of new materials for photophysical and photochemical applications has been explored. Thus, it is important to focus on a deeper understanding of the elctronic energies, transition prohabilities, intermolecular interactions, etc.. This task has been accomplished by leading researchers in the field. They present introductions into, but also detailed reviews of the current state of knowledge of three different subjects.

Alloying Characteristics of the Rare Earth Elements with the Transition Elements
Alloying Characteristics of the Rare Earth Elements with the Transition Elements

Author: Rodney P. Elliot

Publisher:

Published: 1964

Total Pages: 40

ISBN-13:

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The alloying characteristics of the rare earth elements with the transition metals undergo a radical change as the atomic number of the transition series increases - - transition elements in Groups IVa, Va, and VIa are immiscible with the rare earths, while elements of Groups VIIa, and VIIIa, VIIIb, and VIIIc form many compounds. Since this cannot be correlated with a size effect, a reasonable explanation for this behavior is a valency or electronegativity effect. Those binary systems forming compounds form 'Laves phases', which can exist in one of three related crystal structure types: MgCu2, MgZn2, or MgNi2. The specific Laves type crystal structure can be related to the average free electron concentration, a phenomenon which has been used to calculate electronic valency of the transition elements. A compilation of the known Laves-type phases occurring between rare earth elements and transition metals supports the hypothesis that the valency effect is operative. Forty-two additional rare earth-transition metal compounds previously unknown have been prepared and found to be consistent with the previously noted trend with but two exceptions. On the assumption that a critical electron/atom ratio determines which Laves-type structures are stable, the periodical grouping of the Laves-type species of the rare earth-transition metal compounds indicates a slight but regular increase in valency as the atomic number of the rare earth increases. Ternary alloys prepared between the Laves phases of different structure types substantiate the observed valency trend.

Rare Earths-Transition Metals-Boron Compounds
Rare Earths-Transition Metals-Boron Compounds

Author: Emil Burzo

Publisher: Springer Nature

Published: 2023-06-10

Total Pages: 544

ISBN-13: 3030992454

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This book presents advances in the field of rare-earth (R) – transition metal (M) – boron compounds with extensive references. Since titanium and scandium do not form compounds with rare-earths, the Sc/Ti-M-B series are additionally presented. In each chapter the crystal structures, the complex physical properties as determined from neutron diffraction, magnetic measurements, resonance studies, transport properties and band structure calculations are critical analyzed. The models used in describing the experimental evidence are also presented. Tables with the main properties of the R-M-B compounds are given and representative data are illustrated in figures. In this way, the book provides state-of-the art knowledge and a valuable analysis of up-to-date results in the field. The technical applications, as permanent magnets, thermoelectric and magnetocaloric devices, hydrogen storage are also highlighted along with the authors insights into future directions in the field. The book is of interest for scientists involved in the development of the field as well as those working in the technical uses of rare-earth compounds.

Rare-earth Transition-metal Intermetallics
Rare-earth Transition-metal Intermetallics

Author: Mi-Kyung Han

Publisher:

Published: 2006

Total Pages: 452

ISBN-13:

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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.