Magnetic nanostructures / edited by Hari Singh Nalwa

Includes bibliographical references and index

List of Contributors About the Editor Magnetic Semiconductor Nanostructures Wolfram Heimbrodt Peter J. Klar Introduction Fundamental Properties of Bulk Magnetic and Diluted Magnetic Semiconductors Material Preparation and Crystal Structure Bandgap and Optical Properties of Bulk Semiconductors Magnetic Properties of Bulk Semiconductors Magneto-Optical Properties of Bulk Semiconductors Preparation of Magnetic Semiconductor Nanostructures Growth of Epitaxial Layers and Quantum Wells Growth and Preparation of Quantum Wires Growth and Preparation of Quantum Dots Properties of Magnetic and Diluted Magnetic Semiconductor Nanostructures and Ultrafine Particles Optical and Electronic Properties of Magnetic Semiconductor Nanostructures Diluted Magnetic Semiconductor Nanostructures in an External Magnetic Field Spontaneous Magnetization of Magnetic Semiconductor Nanostructures Concluding Remarks and Outlook References Magnetic Nanostructures for Future Magnetic Data Storage: Fabrication and Quantitative Characterization by Magnetic Force Microscopy Axel Carl Eberhard F. Wassermann Introduction Magnetic Data Storage: Method, Aims, Limits Patterned Media for Magnetic Data Storage Periodic Magnetic Dot-Arrays and Their Fabrication Fabrication of Periodic Dot-Arrays with Optical Interference Lithography Periodic Magnetic Dot-Arrays with Various Periodicities Magnetic Properties of Periodic Dot-Arrays Perspectives for Magnetic Dot-Arrays as Future High-Density Storage Media Magnetic Force Microscopy Studies on Magnetic Dot-Arrays An Introduction to Magnetic Force Microscopy Experimental MFM Investigations versus MFM-Image Calculations Semiquantitative MFM Analysis of the Magnetization Reversal Properties of Homogeneous Co/Pt Multilayer Films and Co/Pt Multilayer Dot-Arrays Quantitative Magnetic Force Microscopy Quantitative Analysis of the Magnetic Properties of Single Co/Pt Dots Acknowledgments References Structure and Magnetic Properties of Chemically Ordered Magnetic Binary Alloys in Thin Film Form A. Cebollada R. F. C. Farrow M. F. Toney Introduction Chemical Order in Binary Alloys Long-Range Chemical Order in Alloys Characterization of Chemical Order in Binary Alloys Growth of Chemically Ordered Alloys Procedures to Achieve Long-Range Order in Thin Films In situ and Postgrowth Characterization of Films by Electron Diffraction and Transmission Electron Microscopy Parameters that Control the Degree of Chemical Order Magnetic Anisotropy in Ordered Binary Alloys Microscopic Origin of the Magnetocrystalline Anisotropy First Approach: Anisotropy in Bulk Specimens and Chemical Order Dependence Magnetic Anisotropy in Binary Alloy Thin Films Magnetic Domain Structure of Systems with PMA Applications of High Magnetic Anisotropy Systems Magneto-Optical Activity in Chemically Ordered Binary Alloys MO Effects in Bulk Magnetic Alloys MO Activity in Binary Alloy Thin Films Theoretical Studies Conclusions and Perspectives Acknowledgments References Macroscopic Magnetic Properties of Nanostructured and Nanocomposite Systems Massimo Solzi Massimo Ghidini Giovanni Asti Introduction The Basic Magnetic Properties of Nanostructured Materials Appropriate Scales and Energy Terms The Exchange Interaction Magnetic Anisotropy Dipolar Interaction Magneto-Elastic Interactions Magnetization Structures and Processes in Nanoscaled Systems Scale Length Parameters The Micromagnetic Approach Magnetization Reversal: Coherent Rotation and Nonuniform Processes Magnetic Domains and Domain Walls The Effect of Magnetic Interactions The Magnetization Processes of Nanocomposite Systems Bulk Hard/Soft Nanocomposites Theoretical Models of the Planar Composite Systems Time and Temperature Effects Introduction Superparamagnetism Magnetic Viscosity The Problem of Dynamic Hysteresis Magnetic Susceptibility and Magnetic Phase Transitions The Reversible Susceptibility Tensor The Magnetic Phase Transitions in Nanostructured Materials Macroscopic Measuring Techniques, Both Standard and Special Induction Techniques Force Techniques Magneto-Optical Methods Other Techniques The Singular Point Detection Technique The Magnetic Behavior of Planar Hard/Soft Nanocomposites Exchange-Spring Multilayers as Permanent Magnets The Fe/Co Multilayer as a Model System Other Applications of Planar Nanocomposite Systems Dynamic Hysteresis and Viscosity in Nanocomposite Multilayers Nanostructured Magnetic Systems Obtained by Swift Heavy-Ion Irradiation Introduction Latent Tracks in Rare Earth-Transition Metal Intermetallic Compounds Magnetic Nanocolumns Acknowledgments References Theory of Brillouin Cross Section From Magnetic Nanostructured Multilayers Roberto Zivieri Loris Giovannini Paolo Vavassori Introduction Growth and Characterization Magnetic Superlattices and Multilayers Nanometric Magnetic Structures General Problem Hamiltonian of the System Magnetic Coupling: Bilinear and Biquadratic Exchange Energies Light Interaction with Magnetic Systems: Dielectric Tensor Static Magnetic Properties Magnetic Multilayers Nanometric Magnetic Structures Dynamic Magnetic Properties Spin Wave Equation of Motion Spin Waves in Multilayers and Patterned Structures Thick Films Thin Films Patterned Structures Magneto-Optic Properties Brillouin Scattering Cross Section in Magnetic Multilayers Brillouin Scattering Cross Section in Thin Films Brillouin Scattering Cross Section in Patterned Structures Conclusions and Perspectives Acknowledgments References Dynamics of Nanostructured Magnets R. L. Stamps Introduction and Overview Thermal Dynamics and Relaxation Mean-Field Theory Surface Effects on Magnetic Order Relaxation Times Reversal by Thermal Fluctuations Field-Driven Reversal Types of Order Models of Spin Systems Origins Stoner and Hubbard Models Interlayer Exchange Coupling The Heisenberg Model Connection to Landau Theory Itinerant versus Local Models Linear Dynamics at Long Wavelengths Spin-Wave Excitations in Itinerant Models Long-Wavelength Spin Waves in the Heisenberg Model Semi-Classical Spin Wave Theory Magnetic Anisotropies Magnetostatic Energies Dipole-Exchange Spin Waves and Thin Films Magnetostatic Spin Waves Spin-Wave Interactions: Thermal Behavior and Other Nonlinearities Spin Operators: Bound States and Bosonization Thermal Properties Driven Nonlinear Response Quasi-Static Nonlinear Excitations: Domain Walls and Switching Magnetic Domain Boundary Walls Nucleation Rate Theory Precession-Limited Driven Reversal Relaxation and Scattering Mechanisms Scattering within the Spin System Magnetoelastic Coupling and Phonon Scattering Magnon-Electron Interactions Summary and Outlook Acknowledgments References Off-Axis Electron Holography of Nanostructured Magnetic Materials Rafal E. Dunin-Borkowski Martha R. McCartney Introduction Basis of Off-Axis Electron Holography Imaging Theory Reconstruction of Electron Holograms Magnetic and Mean Inner Potential Contributions to the Phase Experimental Considerations Results Obtained from Optical Reconstruction Co Fine Particle Recorded Magnetic Tape Verification of the Aharonov--Bohm Effect Results Obtained from Digital Reconstruction Lithographically Patterned Magnetic Nanostructures Chains of Magnetic Nanocrystals Magnetic Force Microscopy Tips Cross-Sectional Samples: Removal of Sample Thickness Effects Exchange-Biased Elements Discussion and Conclusions Acknowledgments References Microstructures and Properties of Nanocrystalline and Nanogranular Magnetic Materials K. Hono M.

Ohnuma Introduction Fabrication Methods Nanocrystalline and Nanocomposite Microstructures Metal--Nonmetal Nanogranular Microstructure Properties of Nanocrystalline and Nanogranular Materials Soft Magnetic Properties Hard Magnetic Properties Magnetic Properties Obtained from Granular Microstructure Nanogranular Microstructure Characterization Diffraction and Scattering Techniques The Atom Probe Technique Microstructure--Property Relationship Soft Magnetic Nanocrystalline Alloys Microstructural Evolution in Nanocomposite Magnets Metal--Nonmetal Nanogranular Films Summary Acknowledgments References Hybrid Organic-Inorganic Nanostructured Magnets Mihai A. Girtu Introduction Motivation Goals Outline Magnetic Ordering: Review of Basic Concepts Independent Magnetic Moments Magnetic Interactions Cooperative Behavior and Magnetic Phase Transitions Factors that Influence Magnetic Ordering Magnetic Ordering in Pure and Disordered Systems with and without Frustration Pure Systems without Frustration Disordered Systems without Frustration Disordered Systems with Frustration: Spin Glasses Pure Systems with Frustration Random Field Systems Random Anisotropy Systems Analysis Procedures for Magnetic Experimental Data Analysis Procedures for dc Magnetic Data Analysis Procedures for ac Magnetic Data Molecule-Based Magnets: Novel Materials and Properties Hybrid Organic--Inorganic Magnets Organic Magnets Hybrid Organic--Inorganic Single-Molecule Magnets Molecule-Based Magnets: Novel Phenomena and Opportunities Magnetic Bistability in Hybrid Organic--Inorganic Magnets Multiple Compensation Point Hybrid Organic--Inorganic Magnets Photoinduced Magnetic Effects in Hybrid Organic-Inorganic Magnets High-Coercivity Hybrid Organic--Inorganic Magnets Hybrid Organic--Inorganic Magnetic Conductors Thin Films of Hybrid Organic--Inorganic Magnets Outlook Magnets by Design? A Few Answers and Many Open Questions Trends and Potential Applications Acknowledgments References Preparation, Structure, and Properties of Magnetic Nanocomposite Films H. Wang S. P. Wong Historical Introduction Preparation of Magnetic Nanocomposite Films Conventional Methods Pulsed Filtered Vacuum Arc Deposition Structural and Magnetic Properties of Co-C Nanocomposite Films Microstructure Evolution Magnetic Properties Ordered L10 Phase CoPt- and FePt-Based Nanocomposite Films Overview of High-Ku Materials Phase Transformation of CoPt and FePt Nanocomposite Films Magnetic Properties of CoPt and FePt Nanocomposite Films Read-Write Properties of CoPt and FePt Nanocomposite Films Summary Acknowledgments References Micromagnetics of Nanoparticles and Nanoshaped Magnetic Elements Scott L. Whittenburg Introduction Software Object Oriented Micromagnetics Framework Java MicroMagnetics MagFEM3D LLG Micromagnetics Simulator General Results Cubes Spheres Elliptical Plates Truncated Pyramids and Cylinders Triangles Squares Rings Results for Specific Materials Permalloy Iron Cobalt Nickel Conclusion Acknowledgments References Magnetic and Magnetotransport Properties of Nanostructured Wires and Dots Teruya Shinjo Introduction Sample Preparation Techniques Giant Magnetoresistance (GMR) Studies and Geometry Current at an Angle to the Plane (CAP)-GMR Studies with V-Groove Samples Nanowire Systems Resistivity of a Domain Wall Dot Systems Remarks Acknowledgments References Index