Weinberger Magnetic Anisotropies in Nanostructured Matter

Erscheinungsjahr 2010
ISBN: 978-1-4200-7266-2
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 310 Seiten

Reihe: Condensed Matter Physics

One of the Top Selling Physics Books according to YBP Library Services
Magnetic Anisotropies in Nanostructured Matter presents a compact summary of all the theoretical means to describe magnetic anisotropies and interlayer exchange coupling in nanosystems. The applications include free and capped magnetic surfaces, magnetic atoms on metallic substrates, nanowires, nanocontacts, and domain walls. Some applications also deal with temperature-dependent effects and ab initio magnetization dynamics.

The author clarifies parallel and antiparallel, the distinction between classical spin vectors and spinors, and the actual form of spin–orbit interactions, before showing how symmetry can provide the formal tools to properly define magnetic structures. After these introductory chapters, the book presents methods to describe anisotropic physical properties of magnetic nanostructures. It then focuses on magnetic anisotropy energies, exchange and Dzyaloshinskii–Moriya interactions, temperature-dependent effects, spin dynamics, and related properties of systems nanostructured in one and two dimensions. The book also discusses how methods of describing electric and magneto-optical properties are applied to magnetic nanostructured matter. It concludes with an outlook on emerging magnetic anisotrophic effects.

Written by a leading researcher with over 35 years of experience in the field, this book examines the theory and modeling of magnetic anisotropies in nanostructured materials. It shows how these materials are used in a range of applications.

Zielgruppe

Researchers and graduate students in physics and engineering.

Autoren/Hrsg.

Weinberger, Peter

Fachgebiete

• Technische Wissenschaften Maschinenbau | Werkstoffkunde Maschinenbau

Inhaltsverzeichnis

Introduction

Preliminary Considerations

Parallel, antiparallel, collinear, and noncollinear

Characteristic volumina

"Classical" spin vectors and spinors

The famous spin–orbit interaction

Symmetry Considerations

Translational invariance

Rotational invariance

Colloquial or parent lattices

Tensorial products of spin and configuration

Cell-dependent potentials and exchange fields

Magnetic configurations
Green’s Functions and Multiple Scattering

Resolvents and Green’s functions

The Dyson equation

Scaling transformations

Integrated density of states

Superposition of individual potentials

The scattering path operator
Angular momentum and partial wave representations

Single particle Green’s function

Symmetry aspects

Charge and magnetization densities

Changing the orientation of the magnetization

Screening transformations

The embedded cluster method
The Coherent Potential Approximation

Configurational averages

Restricted ensemble averages

The coherent potential approximation

The single-site coherent potential approximation

Complex lattices and layered systems

Remark with respect to systems nanostructured in two dimensions
Calculating Magnetic Anisotropy Energies

Total energies

The magnetic force theorem

Magnetic dipole–dipole interactions
Exchange and Dzyaloshinskii–Moriya Interactions

The free energy and its angular derivatives
An intermezzo: classical spin Hamiltonians
Relations to relativistic multiple scattering theory
The Disordered Local Moment Method (DLM)

The relativistic DLM method for layered systems

Approximate DLM approaches

Spin Dynamics

The phenomenological Landau–Lifshitz–Gilbert equation

The semiclassical Landau–Lifshitz equation

Constrained density functional theory

The semiclassical Landau–Lifshitz–Gilbert equation

First principles spin dynamics for magnetic systems nanostructured in two dimensions
The Multiple Scattering Scheme

The quantum mechanical approach

Methodological aspects in relation to magnetic anisotropies

Physical properties related to magnetic anisotropies

Nanostructured in One Dimension: Free and Capped Magnetic Surfaces

Reorientation transitions
Trilayers, interlayer exchange coupling
Temperature dependence

A short summary
Nanostructured in One Dimension: Spin Valves

Interdiffusion at the interfaces

Spin valves and noncollinearity
Switching energies and the phenomenological Landau–Lifshitz–Gilbert equation
Heterojunctions
Summary
Nanostructured in Two Dimensions: Single Atoms, Finite Clusters, and Wires

Finite clusters

Finite wires and chains of magnetic atoms

Aspects of noncollinearity
Nanostructured in Two Dimensions: Nanocontacts, Local Alloys
Quantum corrals

Magnetic adatoms and surface states

Nanocontacts

Local alloys

Summary
A Mesoscopic Excursion: Domain Walls

Theory of Electric and Magneto-Optical Properties
Linear response theory

Kubo equation for independent particles

Electric transport—the static limit

The Kubo–Greenwood equation

Optical transport
Electric Properties of Magnetic Nanostructured Matter

The bulk anisotropic magnetoresistance (AMR)

Current-in-plane (CIP) and the giant magnetoresistance (GMR)

Current-perpendicular to the planes of atoms (CPP)

Tunneling conditions

Spin-valves

Heterojunctions

Systems nanostructured in two dimensions

Domain wall resistivities

Summary
Magneto-Optical Properties of Magnetic Nanostructured Matter
The macroscopic model
The importance of the substrate

The Kerr effect and interlayer exchange coupling

The Kerr effect and magnetic anisotropy energy

The Kerr effect in the case of repeated multilayers

How surface sensitive is the Kerr effect?

Summary
Time Dependence

Terra incognita

Pump-probe experiments

Pulsed electric fields

Spin currents and torques

Instantaneous resolvents and Green’s functions

Time-dependent multiple scattering
Physical effects to be encountered

Expectations
Afterword
Index