Disordered Alloys

Disordered Alloys PDF Author: Werner Schweika
Publisher: Springer Science & Business Media
ISBN: 9783540634454
Category : Science
Languages : en
Pages : 144

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Book Description
This monograph reviews the subject of structural disorder in alloys and describes how structural information can be exploited to build sound theoretical descriptions in terms of modified Ising models. Scattering with thermal neutrons and x-rays prove to be complementary approaches to measure the weak diffuse scattering which provides detailed information about the disorder. The authors show how Monte Carlo methods are applied to determine the most realistic effective interactions among the alloying atoms. These results can be used as a benchmark for modern electronic structure calculations. Of more general interest, the limitations of scattering experiments in a determination of an interaction model, and thus also of the structure itself are discussed. Finally, simulations exhibit not only near-surface disordering due to frustration effects but also new possible surface - induced ordering phenomena. Accurate Monte Carlo simulations are used to test existing theories of wetting.

Disordered Alloys

Disordered Alloys PDF Author: Werner Schweika
Publisher: Springer Science & Business Media
ISBN: 9783540634454
Category : Science
Languages : en
Pages : 144

Get Book Here

Book Description
This monograph reviews the subject of structural disorder in alloys and describes how structural information can be exploited to build sound theoretical descriptions in terms of modified Ising models. Scattering with thermal neutrons and x-rays prove to be complementary approaches to measure the weak diffuse scattering which provides detailed information about the disorder. The authors show how Monte Carlo methods are applied to determine the most realistic effective interactions among the alloying atoms. These results can be used as a benchmark for modern electronic structure calculations. Of more general interest, the limitations of scattering experiments in a determination of an interaction model, and thus also of the structure itself are discussed. Finally, simulations exhibit not only near-surface disordering due to frustration effects but also new possible surface - induced ordering phenomena. Accurate Monte Carlo simulations are used to test existing theories of wetting.

Electronic Structure of Disordered Alloys, Surfaces and Interfaces

Electronic Structure of Disordered Alloys, Surfaces and Interfaces PDF Author: Ilja Turek
Publisher: Springer Science & Business Media
ISBN: 1461562554
Category : Science
Languages : en
Pages : 327

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Book Description
At present, there is an increasing interest in the prediction of properties of classical and new materials such as substitutional alloys, their surfaces, and metallic or semiconductor multilayers. A detailed understanding based on a thus of the utmost importance for fu microscopic, parameter-free approach is ture developments in solid state physics and materials science. The interrela tion between electronic and structural properties at surfaces plays a key role for a microscopic understanding of phenomena as diverse as catalysis, corrosion, chemisorption and crystal growth. Remarkable progress has been made in the past 10-15 years in the understand ing of behavior of ideal crystals and their surfaces by relating their properties to the underlying electronic structure as determined from the first principles. Similar studies of complex systems like imperfect surfaces, interfaces, and mul tilayered structures seem to be accessible by now. Conventional band-structure methods, however, are of limited use because they require an excessive number of atoms per elementary cell, and are not able to account fully for e.g. substitu tional disorder and the true semiinfinite geometry of surfaces. Such problems can be solved more appropriately by Green function techniques and multiple scattering formalism.

Order-Disorder Transformations in Alloys

Order-Disorder Transformations in Alloys PDF Author: H. Warlimont
Publisher: Springer Science & Business Media
ISBN: 3642808409
Category : Technology & Engineering
Languages : en
Pages : 554

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Book Description
This book contains 18 invited contributions to the first Inter national Symposium on Order-Disorder Transformations in Alloys+. They cover the major aspects of this group of phase transformations. Although structural order-disorder transformations have been investigated for over 50 years the invited papers, the research papers - whose titles and authors are listed in the appendix - and the discussions at the Symposium have demonstrated very active continued interest and con siderable recent progress in the subject. This is true for theoretical work as weIl as for experimental studies and for the development of materials whose properties result from order-disorder transformations. + Some major national conferences on ordering were held in the USA and in the USSR in recent years; the proceedings are available in the following pUblications: Local Atomic Arrangements Studied by X-Ray Diffraction, Gordon & Breach, New York 1966 2 Ordered Alloys, Claitor's Publ. Div. , Baton Rouge, La. 1970 3 Summaries of the Proceedings of the 2nd Union Conference on Atomic Ordering and its Influence on the Properties of Alloys, Naukova Dumka, Kiev 1966 4 Atomic Ordering and its Influence on the Properties of Alloys, Naukova Dumka, Kiev 1968 5 Atomic Ordering and its Influence on the Properties of Alloys, TGU, Tomsk 1973 111 In assembling these papers it vas attempted to compile a systematic and approximately complete compendium of the sUbject.

Alloys and Intermetallic Compounds

Alloys and Intermetallic Compounds PDF Author: Cristina Artini
Publisher: CRC Press
ISBN: 1498741444
Category : Science
Languages : en
Pages : 368

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Book Description
This book focuses on the role of modeling in the design of alloys and intermetallic compounds. It includes an introduction to the most important and most used modeling techniques, such as CALPHAD and ab-initio methods, as well as a section devoted to the latest developments in applications of alloys. The book emphasizes the correlation between modeling and technological developments while discussing topics such as wettability of Ultra High Temperature Ceramics by metals, active brazing of diamonds to metals in cutting tools, surface issues in medicine, novel Fe-based superconductors, metallic glasses, high entropy alloys, and thermoelectric materials.

Semiconductor Alloys

Semiconductor Alloys PDF Author: An-Ben Chen
Publisher: Springer Science & Business Media
ISBN: 1461303176
Category : Science
Languages : en
Pages : 358

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Book Description
In the first comprehensive treatment of these technologically important materials, the authors provide theories linking the properties of semiconductor alloys to their constituent compounds. Topics include crystal structures, bonding, elastic properties, phase diagrams, band structures, transport, ab-initio theories, and semi-empirical theories. Each chapter includes extensive tables and figures as well as problem sets.

Progress in Metallic Alloys

Progress in Metallic Alloys PDF Author: Vadim Glebovsky
Publisher: BoD – Books on Demand
ISBN: 9535126962
Category : Technology & Engineering
Languages : en
Pages : 300

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Book Description
In general, metallic alloys are the interdisciplinary subject or even an area that cover physics, chemistry, material science, metallurgy, crystallography, etc. This book is devoted to the metallic alloys. The primary goal is to provide coverage of advanced topics and trends of R

Ordering and Disordering in Alloys

Ordering and Disordering in Alloys PDF Author: A.R. Yavari
Publisher: Springer Science & Business Media
ISBN: 9401128863
Category : Technology & Engineering
Languages : en
Pages : 524

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Book Description
Proceedings of the European Workshop on Ordering and Disordering held in Grenoble, France, 10-12 July 1991.

Disordered Alloys

Disordered Alloys PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Electronic Structure of Alloys, Surfaces and Clusters

Electronic Structure of Alloys, Surfaces and Clusters PDF Author: Abhijit Mookerjee
Publisher: CRC Press
ISBN: 9780415272490
Category : Technology & Engineering
Languages : en
Pages : 396

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Book Description
Understanding the electronic structure of solids is a basic part of theoretical investigation in physics. Application of investigative techniques requires the solid under investigation to be "periodic." However, this is not always the case. This volume addresses three classes of "non-periodic" solids currently undergoing the most study: alloys, surfaces and clusters. Understanding the electronic structure of these systems is fundamental not only for the basic science, but also constitutes a very important step in various technological aspects, such as tuning their stabilities, chemical and catalytic reactivities and magnetism. Expert practitioners give an up-to-date account of the field with enough detailed background so that even a newcomer can follow the development. The theoretical framework is discussed in addition to the present status of knowledge in the field. Electronic Structure of Alloys, Surfaces and Clusters also includes an extensive bibliography which provides a comprehensive reading list of work on the topic.

Properties of multilayered and multicomponent nitride alloys from first principles

Properties of multilayered and multicomponent nitride alloys from first principles PDF Author: Fei Wang
Publisher: Linköping University Electronic Press
ISBN: 9176853829
Category :
Languages : en
Pages : 86

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Book Description
This thesis is a theoretical exploration of properties of multilayered and multicomponent nitride alloys, in particular their mixing thermodynamics and elastic behaviors. Systematic investigation of properties of a large class of materials, such as the multicomponent nitride solid solutions, is in line with the modern approach of high-throughput search of novel materials. In this thesis we benchmark and utilize simple but efficient methodological frameworks in predicting mixing thermodynamics, Young’s moduli distribution of multilayer alloys and the linear thermal expansion of quaternary nitride solid solutions. We demonstrate by accurate ab-initio calculations that Ti1−xAlxN solid solution is stabilized by interfacial effects if it is coherently sandwiched between TiN layers along (001). For TiN/AlN and ZrN/AlN multilayers we show higher thermodynamic stability with semicoherent interfaces than with isostructural coherent ones. Accurate 0 Kelvin elastic constants of cubic TixXyAl1−x−yN (X=Zr, Hf, Nb, V, Ta) solid solutions and their multilayers are derived and an analytic comparison of strengths and ductility are presented to reveal the potential of these materials in hard coating applications. The Young’s moduli variation of the bulk materials has provided a reliable descriptor to screen the Young’s moduli of coherent multilayers. The Debye model is used to reveal the high-temperature thermodynamics and spinodal decomposition of TixNbyAl1−x−yN. We show that though the effect of vibration is large on the mixing Gibbs free energy the local spinoal decomposition tendencies are not altered. A quasi-harmonic Debye model is benchmarked against results of molecular dynamics simulations in predicting the thermal expansion coefficients of TixXyAl1−x−yN (X=Zr, Hf, Nb, V, Ta). Denna avhandling är en teoretisk undersökning av egenskaperna hos multilager och multikomponentlegeringar av nitrider, särskilt deras blandningstermodynamik och elastiska egenskaper. Systematiska undersökningar av egenskaperna hos en stor materialfamilj, såsom fasta lösningar av multikomponentnitrider, ligger i linje med den moderna angreppsvinkeln av massundersökningar i sökandet efter nya material. I denna avhandling utvärderar och använder vi enkla men effektiva metodologiska ramverk för att förutsäga blandningstermodynamik, fördelning av Young’s moduli multilager och den linjära termiska expansionen i kvaternära fasta lösningar av nitrider. Vi visar med precisa ab-initio-beräkningar att en fast lösning av Ti1−xAlxN stabiliseras av gränssnittseffekter om den placeras koherent mellan TiN-skikt längs med (001). För multilager av TiN/AlN och ZrN/AlN påvisar vi högre termodynamisk stabilitet med semikoherenta gränsskikt än med isostrukturella koherenta. Precisa elastiska konstanter vid 0 K för kubiska fasta lösningar av TixXyAl1−x−yN (X=Zr, Hf, Nb, V, Ta) och deras multilager beräknas och en analytisk jämförelse av deras hållfasthet och duktilitet presenteras för att visa dessa materials potential som hårda beläggningar. Variationen av Young’s moduli materialen i bulk har gett en pålitlig deskriptor för att undersöka Young’s moduli koherenta multilager. Debye-modellen används för att undersöka hög-temperatur-termodynamiken och spinodalt sönderfall hos TixNbyAl1−x−yN. Vi visar att trots att vibrationers effekt på Gibbs fria energi för blandning är stor påverkas inte de lokala tendenserna för spinodalt sönderfall. En kvasiharmonisk Debye-modell jämförs med resultat från molekyldynamiksimuleringar för att förutsäga utvidgningskoefficienter för TixXyAl1−x−yN (X=Zr, Hf, Nb, V, Ta). Diese Arbeit ist eine theoretische Untersuchung der Eigenschaften von mehrschichtigen und mehrkomponentigen Nitridlegierungen, insbesondere deren Mischungs- Thermodynamik und elastischen Verhalten. Eine systematische Untersuchung von Eigenschaften einer großen Klasse von Materialien, wie zum Beispiel fester Lösungen von Mehrkomponenten-Nitriden, ist im Einklang mit dem zeitgenössischen Hochdurchsatzverfahren für die Suche nach neuen Materialien. In dieser Arbeit benchmarken und nutzen wir einfache, aber effiziente methodische Frameworks zur Vorhersage der Mischungs-Thermodynamik, der Verteilung des Elastizitätsmoduls von Mehrschichtlegierungen und der linearen thermischen Ausdehnung von festen, quaternären Nitrid-Lösungen. Wir zeigen durch genaue Ab-initio-Berechnungen, dass Ti1−xAlxN Mischkristalle durch Grenzflächenwirkungen stabilisiert werden, wenn sie kohärent zwischen TiN Schichten entlang (001) sandwichartig angeordnet sind. Die genauen elastischen Konstanten von kubischen TixXyAl1−x−yN (X = Zr, Hf, Nb, V, Ta) Mischkristallen und deren Mehrfachschichten bei 0 Kelvin werden abgeleitet und ein analytischer Vergleich der Festigkeit und Duktilität zeigt das Potential dieser Materialien in Hartbeschichtungsanwendungen. Das Debye-Modell wird verwendet, um die Hochtemperatur-Thermodynamik und die spinodale Entmischung von TixNbyAl1−x−yN aufzudecken. Wir zeigen, dass sich die lokale Tendenzen zur spinodalen Entmischung nicht ändern, obwohl die Wirkung von Vibrationen auf die Gibbs-Energie großist. Ein quasi-harmonisches Debye-Modell wird gegen die Ergebnisse von Moleküldynamik-Simulationen gebenchmarkt, um die thermische Ausdehnungskoeffizienten von TixXyAl1−x−yN (X=Zr, Hf, Nb, V, Ta) vorherzusagen.