| 1 |
Introduction
Course Ground Rules and Overview
Approach: Microscopic to Macroscopic, Impact of Magnetism on Technology (Power, Recording, Magneto-mechanical, Transportation, Security, Sensors, Actuators), Basic Scientific Questions in Magnetism |
1.2, 1.3.2, 1.4, 1.4.3, 1.5, 1.6.1 |
| Classical Magnetism |
| 2 |
Magnetostatics
Origin of Magnetic Fields in and about Magnetized Materials
Maxwell's Equations Give Boundary Conditions on B and H |
2.1-2.4 |
| 3 |
Magnetostatics (cont.)
Demagnetization Factors
Quantitative Magnetostatics and Fields Due to Periodic Domains |
2.6 |
| 4 |
Where Do Magnetic Moments Come From?
Classical Free Electron Theory of Magnetism
Orbital Gyromagnetic Ratio
Diamagnetism, Paramagnetism |
3.1-3.3, 3.4-3.5 (light), 3.5.2 |
| Quantum Mechanics and Magnetism in Oxides and Metals |
| 5 |
Spin, Anomalous Zeeman Effect, and Ferromagnetism
Spin Quantum Numbers: l, s, j
Gyromagnetic Ratios for Orbital and Spin Moments
Quantum Theory of Paramagnetism
Extend Quantum Paramagnet via Graphical and Analytic Solution for Brillouin Function for Ferromagnetism |
3.5.3, 3.6 (skip 3.6.1, 3.6.2), 3.7.1, 3.7.2 |
| 6 |
Exchange in Insulators
Quantum Origin of Magnetism
Intra-atomic, Hund's Rules
Superexchange, in Oxides, Internal Pressure of Magnetism |
4.1 (concepts), Fig. 4.3, 4.1.6, 4.2, 4.3, 4.4 |
| 7 |
Bonding and Magnetism
Molecular Orbitals in Metals
Slater Pauling Curves, Curie Temperature
Band Theories of Magnetism |
5.1, 5.2, 5.3 (partial), 5.4-5.6 |
| Magnetic Energies |
| 8 |
Magnetic Anisotropy
Magnetic Anistropy Data, Energy to Magnetize, Phenomenology
Ingredients of Magnetic Anisotropy
Anisotropy in Metals and Insulators, Temperature Dependence |
6.1, 6.2, 6.3 (concepts), 6.4(concepts), 6.5 (refer to 2.5) |
| 9 |
Torque Measurement of Magnetic Anisotropy
Observations of Magnetostriction, Macroscopic Phenomenology, Data for Metals and Oxides
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7.1, 7.2 (some quant.), 7.3, 7.4 (concepts) |
| 10 |
Magnetoelastic Anisotropy
Influence of Stress on Magnetization
Temperature Dependence
Measurement Techniques |
7.5-7.6 (concept), 7.7
Appendix 7A (summary of Zeeman, anisotropy) |
| 11 |
Magnetic Domain Walls and Domains
Exchange Energy, Width and Energy Density of Domain Walls
Bloch vs. Néel Walls |
8.1, 8.2, 8.3.2, 8.4, 8.5, 8.5.1 |
| 12 |
Magnetic Domains
Magnetic Domains, Closure Domains, Domains in Thin Films and Fine Particles
Single Domain Particles, Superparamagnetism |
8.6, 8.7 |
| 13 |
Lab Experience
M-H Hysteresis Loops using Vibrating Sample Magnetometer (VSM)
Magnetization versus Field and Temperature using VSM
Torque Curves for Magnetic Anisotropy using Torque Magnetometer |
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| 14 |
Analysis and Discussion of Lab Results |
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| 15 |
Magnetization Processes
Macroscopic Quasistatic Approach: Applied Field, Anisotropy, Magneostriction, and Dipole Energies
Euler Equations and Boundary Conditions to Calculate Reversible Rotation
Emphasize How Anisotropy, Magnetostriction, Resistivity affect Soft Magnetic Behavior
Microwave Magnetism Ferromagnetic Resoanance |
9.1, 9.2, 9.3.1 -9.3.3, 9.4 (qualitative), 9.5 |
| 16 |
Written Mid-term Exam |
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| Magnetic Materials and Applications |
| 17 |
Soft Ferromagnetic Materials Behavior
Soft Ferromagnetic Materials Behavior, Si-Fe, Fe-Ni, Fe-Co Alloys and Soft Ferrites
Amorphous and Nanocrystalline Alloys
DC Rotation Permeability, Irreversible Rotation
AC Behavior, Skin Depth, Applications
Hysteresis Loss and Eddy Current Loss |
10.1-10.6 |
| 18 |
Amorphous Magnetism
Amorphous Magnetism, Competing Interactions
Exchange Fluctuations, Random Anisotropy, Resistivity
Models of Amorphous Magnetism, Alloy Effects vs. Disorder |
11.1, 11.2, 11.4.1, 11.4.3, 11.5 |
| 19 |
Nanocrystalline Magnetic Materials
Exchange Fluctuations, Random Anisotropy Effects on Properties with Length Scale |
12.1-12.3 |
| 20 |
Hard Magnetic Materials
M-H, B-H, (B-H)max, Fine Particles, Nucleation, Pinning
Materials: Alnico, Ba Ferrite, Co-RE, Fe-RE-B |
13.1, 13.2 (concept), 13.4, 13.5 |
| 21 |
Transport in Magnetic Materials
Electrical Conductivity of Metals and Alloys in Light of Electronic Structure
Hall Effect and Magnetoresistance (MR), MR Heads, Mechanisms of Spin Scattering, Giant MR, Spin Tunneling |
15.1-15.6, 15.7 (concept) |
| 22 |
Surface and Thin Film Magnetism
Surface Electronic Structure and Magnetism, Surface Moments, Metastable Phases, Misfit Strain, Epitaxial Growth, Surface Magnetic Anisotropy and Magnetostriction, Domains, Devices |
16.1-16.4 |
| 23 |
Magnetic Recording
Physics of Recording
Basic Concepts of Recording Media and Heads, Karlkvist Fields, Noise |
17.1-17.4 |
| 24 |
Magnetic Recording Materials
Particulate: y Fe2O3 CrO2, Co-Ferric Oxide, Barium Ferrite
Thin Film Media: Longitudinal, Perpendicular
Thin Film Heads, MR Heads, Spin Valves, Magnetic Random Access Memories |
17.5-17.6 |
| 25-26 |
Oral Presentations by Students (20-30 minutes) |
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