Quantum spin fluctuation theory of the magnetic equation of state of weak itinerant-electron ferromagnets
Quantum spin fluctuation theory of the magnetic equation of state of weak itinerant-electron ferromagnets
复制标题
弱巡回电子铁磁体磁状态方程的量子自旋涨落理论
DOI：
--
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Y. Takahashi
中科院分区：
文献类型：
--
作者：
Y. Takahashi
在自旋涨落机制的基础上，考虑了零点量子自旋涨落的影响，讨论了从基态到顺磁态的宽温度范围内巡游电子弱铁磁体的磁性.特别注意的是集中在有序相的属性。自发磁矩的温度依赖性，例如，定量分析与实验密切比较。它还表明，四阶膨胀系数的自由能的功率的静磁矩是温度依赖性的，因此，磁性等温线是不是那么简单，原来预期的Stoner-Wohlfarth理论。我们明确检查的自旋波模式上的横向自旋波动幅度的影响，并表明，这种效果是至关重要的适当的理论描述有序状态下的磁性行为。
On the basis of the spin fluctuation mechanism, magnetic properties of itinerant-electron weak ferromagnets are discussed, for the wide temperature range from the ground state to the paramagnetic state, explicitly taking into account the effects of zero-point quantum spin fluctuations. Particular attention is focused on properties of the ordered phase. The temperature dependence of the spontaneous magnetic moment, for instance, is quantitatively analysed in close comparison with experiments. It is also shown that the fourth-order expansion coefficient of the free energy in powers of the static magnetic moment is temperature dependent, and therefore magnetic isotherms are not so simple as was originally anticipated in the Stoner–Wohlfarth theory. We explicitly examine the effect of the spin-wave mode on the transverse spin fluctuation amplitude, and show that this effect is crucial for the proper theoretical description of magnetic behaviours in the ordered state.