Spin Fluctuations in Itinerant Electron Magnetism

1. Front Matter

   Pages I-X

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2. Introduction

   • Tôru Moriya

   Pages 1-14

3. Mean-Field Theory of Itinerant Electron Magnetism

   • Tôru Moriya

   Pages 15-29

4. Dynamical Mean-Field Theory of Spin Fluctuations

   • Tôru Moriya

   Pages 30-43

5. Self-Consistent Renormalization (SCR) Theory of Spin Fluctuations

   • Tôru Moriya

   Pages 44-81

6. Physical Properties of Weakly and Nearly Ferro- and Antiferromagnetic Metals

   • Tôru Moriya

   Pages 82-108

7. Local Magnetic Moments

   • Tôru Moriya

   Pages 109-128

8. A Unified Theory and Its General Consequences

   • Tôru Moriya

   Pages 129-156

9. Functional Integral Theory

   • Tôru Moriya

   Pages 157-193

10. Spin Fluctuations in d-Electron Systems

    • Tôru Moriya

    Pages 194-213

11. Toward a Unified Theory of Dynamical Spin Fluctuations

    • Tôru Moriya

    Pages 214-222

12. Concluding Remarks

    • Tôru Moriya

    Pages 223-224

13. Back Matter

    Pages 225-243

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Ferromagnetism of metallic systems, especially those including transition metals, has been a controversial subject of modern science for a long time. This controversy sterns from the apparent dual character of the d-electrons responsible for magnetism in transition metals, i.e., they are itinerant elec­ trons described by band theory in their ground state, while at finite tem­ peratures they show various properties that have long been attributed to a system consisting of local magnetic moments. The most familiar example of these properties is the Curie-Weiss law of magnetic susceptibility obeyed by almost all ferromagnets above their Curie temperatures. At first the problem seemed to be centered around whether the d-elec­ trons themselves are localized or itinerant. This question was settled in the 1950s and early 1960s by various experimental investigations, in particular by observations of d-electron Fermi surfaces in ferromagnetic transition metals. These observations are generally consistent with the results of band calculations. Theoretical investigations since then have concentrated on explaining this dual character of d-electron systems, taking account of the effects of electron-electron correlations in the itinerant electron model. The problem in physical terms is to study the spin density fluctuati·ons, which are ne­ glected in the mean-field or one-electron theory, and their influence on the physical properties.

• Electron Magnetism
• Spin
• band structure
• band theory
• electron
• electron correlations
• magnetism
• magnetization
• phase transition
• scattering
• semiconductor

• Institute of Solid State Physics, University of Tokyo, Roppongi, Minato-ku, Tokyo 106, Japan

  Tôru Moriya

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