Model for exchange bias in polycrystalline ferromagnet-antiferromagnet bilayers
Model for exchange bias in polycrystalline ferromagnet-antiferromagnet bilayers
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DOI：
10.1103/physrevb.59.3722
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发表时间：
1999-02-01
影响因子：
3.7
通讯作者：
McMichael, RD
中科院分区：
文献类型：
--
作者：
Stiles, MD;McMichael, RD
本文描述了一个多晶铁磁-反铁磁双层膜的模型。独立的反铁磁颗粒耦合到铁磁膜的直接耦合到净力矩在界面处的颗粒和自旋翻转耦合。铁磁磁化的旋转在每个晶粒的界面处向反铁磁自旋施加扭矩，该扭矩卷起反铁磁体中的部分畴壁。该模型解释了单向各向异性，引起了众所周知的移位磁滞回线，以及在旋转扭矩和铁磁共振实验中观察到的滞后效应。单向各向异性来自于当磁化旋转时反铁磁序稳定的晶粒。滞后效应来自于晶粒中的反铁磁顺序不可逆地切换作为畴壁是过去的一个假设的临界角卷起。对于这里考虑的所有模型，自旋触发器耦合不有助于单向各向异性。[S0163-1829（99）01305-3]。
This paper describes a model for polycrystalline ferromagnet-antiferromagnet bilayers. Independent antiferromagnetic grains are coupled to a ferromagnetic film both by direct coupling to the net moments at the interfaces of the grains and by spin-flop coupling. Rotation of the ferromagnetic magnetization applies a torque to the antiferromagnetic spins at the interface of each grain which winds up partial domain walls in the antiferromagnet. The model explains both the unidirectional anisotropy that gives rise to the well-known shifted hysteresis loops, and the hysteretic effects observed in rotational torque and ferromagnetic resonance experiments. The unidirectional anisotropy comes from grains in which the antiferromagnetic order is stable as the magnetization is rotated. The hysteretic effects come from grains in which the antiferromagnetic order irreversibly switches as the domain wall is wound up past a postulated critical angle. For all of the models considered here, spin-flop coupling does not contribute to the unidirectional anisotropy. [S0163-1829(99)01305-3].