ZERO-POINT SPIN FLUCTUATIONS AND THE MAGNETOVOLUME EFFECT IN ITINERANT-ELECTRON MAGNETISM

被引:37
作者
SOLONTSOV, AZ [1 ]
WAGNER, D [1 ]
机构
[1] RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY
来源
PHYSICAL REVIEW B | 1995年 / 51卷 / 18期
关键词
D O I
10.1103/PhysRevB.51.12410
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Quantum dynamical effects of zero-point spin fluctuations (SF) are shown to give rise to the strong spin anharmonicity effects neglected in the conventional SF theory of weak itinerant-electron magnetism, which is based on the weak SF coupling constraint. A theory of weak itinerant magnets is presented generalizing the quantum Ginzburg-Landau (GL) approach to account for large zero-point SF and spin anharmonicity effects in a wide temperature range both below and far above the Curie temperature. The theory is based on a variational procedure for the free energy treated as a functional of the magnetic susceptibilities which are defined self-consistently via the free energy. The magnetic equation of state and magnetovolume effect are analyzed in terms of thermal and zero-point SF. The theory presents the microscopic grounds for the phenomenological GL approach where the zero-point SF effects are incorporated in the model parameters and establishes a new link between the SF theory and the first-principles band-structure calculations. © 1995 The American Physical Society.
引用
收藏
页码:12410 / 12417
页数:8
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