Etude des propriétés magnétiques de super-réseaux Dy/Tb par simulations numériques Monte Carlo

Etude des propriétés magnétiques de super-réseaux Dy/Tb par simulations numériques Monte Carlo PDF Author: Pierre Verdier
Publisher:
ISBN:
Category :
Languages : fr
Pages : 189

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Book Description
L'étude des propriétés magnétiques de super-réseaux Dysprosium (Dy)/Terbium (Tb) par simulations numériques Monte Carlo a été motivée par l'existence de courbes expérimentales de variation thermique de l'aimantation, présentant un maximum et un minimum dépendant du super-réseau. Le Hamiltonien retenu est la somme d'un terme d'échange, d'un terme d'anisotropie planaire présente dans les terres rares, et d'un terme d'interaction Zeeman. L'existence de nombreux états métastables a rendu cette étude délicate, et nous a conduit à utiliser le calcul parallèle. Nos résultats montrent que la phase hélimagnétique présente dans les couches de Dy permet d'expliquer qualitativement les comportements expérimentaux observés. En particulier, la hauteur et la position des maximum et minimum sont très dépendantes du nombre de plans de Dy mais peu sensibles au nombre de plans de Tb.

Etude des propriétés magnétiques de multicouches Fe/Dy par simulations numériques Monte-Carlo

Etude des propriétés magnétiques de multicouches Fe/Dy par simulations numériques Monte-Carlo PDF Author: Etienne Talbot (enseignant-chercheur en physique des matériaux).)
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

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Book Description
Les multicouches Fe/Dy présentent une anisotropie magnétique perpendiculaire au plan des couches qui semble fortement corrélée à la formation d'un alliage amorphe Fe-Dy à l'interface. Le but de ce travail est d'étudier les propriétés magnétiques de ces systèmes par simulations Monte Carlo pour différents types d'interfaces. Nous mettons en évidence l'existence d'un profil d'aimantation inhomogène en épaisseur qui dépend du profil de concentration. Nos résultats sont en bon accord avec les résultats expérimentaux, en particulier sur l'ouverture des cycles d'hystérésis lorsque le champ est appliqué dans le plan des couches en raison de l'influence de l'anisotropie aléatoire. Pour un champ magnétique appliqué perpendiculairement au plan des couches, les cycles d'hystérésis sont caractéristiques d'une anisotropie perpendiculaire

Langevin Equation, The: With Applications To Stochastic Problems In Physics, Chemistry And Electrical Engineering (2nd Edition)

Langevin Equation, The: With Applications To Stochastic Problems In Physics, Chemistry And Electrical Engineering (2nd Edition) PDF Author: William T Coffey
Publisher: World Scientific
ISBN: 981448539X
Category : Science
Languages : en
Pages : 704

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Book Description
This volume is the second edition of the first-ever elementary book on the Langevin equation method for the solution of problems involving the Brownian motion in a potential, with emphasis on modern applications in the natural sciences, electrical engineering and so on. It has been substantially enlarged to cover in a succinct manner a number of new topics, such as anomalous diffusion, continuous time random walks, stochastic resonance etc, which are of major current interest in view of the large number of disparate physical systems exhibiting these phenomena. The book has been written in such a way that all the material should be accessible to an advanced undergraduate or beginning graduate student. It draws together, in a coherent fashion, a variety of results which have hitherto been available only in the form of research papers or scattered review articles.

Symmetric Galerkin Boundary Element Method

Symmetric Galerkin Boundary Element Method PDF Author: Alok Sutradhar
Publisher: Springer Science & Business Media
ISBN: 3540687726
Category : Technology & Engineering
Languages : en
Pages : 276

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Book Description
Symmetric Galerkin Boundary Element Method presents an introduction as well as recent developments of this accurate, powerful, and versatile method. The formulation possesses the attractive feature of producing a symmetric coefficient matrix. In addition, the Galerkin approximation allows standard continuous elements to be used for evaluation of hypersingular integrals. FEATURES • Written in a form suitable for a graduate level textbook as well as a self-learning tutorial in the field. • Covers applications in two-dimensional and three-dimensional problems of potential theory and elasticity. Additional basic topics involve axisymmetry, multi-zone and interface formulations. More advanced topics include fluid flow (wave breaking over a sloping beach), non-homogeneous media, functionally graded materials (FGMs), anisotropic elasticity, error estimation, adaptivity, and fracture mechanics. • Presents integral equations as a basis for the formulation of general symmetric Galerkin boundary element methods and their corresponding numerical implementation. • Designed to convey effective unified procedures for the treatment of singular and hypersingular integrals that naturally arise in the method. Symbolic codes using Maple® for singular-type integrations are provided and discussed in detail. • The user-friendly adaptive computer code BEAN (Boundary Element ANalysis), fully written in Matlab®, is available as a companion to the text. The complete source code, including the graphical user-interface (GUI), can be downloaded from the web site http://www.ghpaulino.com/SGBEM_book. The source code can be used as the basis for building new applications, and should also function as an effective teaching tool. To facilitate the use of BEAN, a video tutorial and a library of practical examples are provided.

Stochastic Processes in Nonequilibrium Systems

Stochastic Processes in Nonequilibrium Systems PDF Author: L. Garrido
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 386

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Book Description


Quantum Mechanics, Volume 3

Quantum Mechanics, Volume 3 PDF Author: Claude Cohen-Tannoudji
Publisher: John Wiley & Sons
ISBN: 3527345558
Category : Science
Languages : en
Pages : 790

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Book Description
This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.

Flexoelectricity in Liquid Crystals

Flexoelectricity in Liquid Crystals PDF Author: Agnes Buka
Publisher: World Scientific
ISBN: 1848167997
Category : Science
Languages : en
Pages : 299

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Book Description
The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Subcritical Assemblies

Subcritical Assemblies PDF Author: W. Maurice Pritchard
Publisher:
ISBN:
Category : Nuclear science
Languages : en
Pages : 48

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Book Description


Application of the Single Failure Criterion

Application of the Single Failure Criterion PDF Author: International Atomic Energy Agency
Publisher:
ISBN:
Category : Business & Economics
Languages : en
Pages : 82

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Book Description


CIKM'13

CIKM'13 PDF Author: CIKM 13 Conference Committee
Publisher:
ISBN: 9781450326964
Category : Computers
Languages : en
Pages : 938

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Book Description
CIKM'13: 22nd ACM International Conference on Information and Knowledge Management Oct 27, 2013-Nov 01, 2013 San Francisco, USA. You can view more information about this proceeding and all of ACM�s other published conference proceedings from the ACM Digital Library: http://www.acm.org/dl.