Intrinsic exchange biasing in MnAs epilayers grown on (001) GaAs
Intrinsic exchange biasing in MnAs epilayers grown on (001) GaAs
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(001) GaAs 上生长的 MnAs 外延层的本征交换偏压
DOI：
10.1063/1.1367306
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发表时间：
2001
影响因子：
4
通讯作者：
N. Samarth
中科院分区：
文献类型：
--
作者：
S. Chun;S. Potashnik;K. Ku;J. Berry;P. Schiffer;N. Samarth
本文研究了用分子束外延方法在GaAs（001）衬底上以两种择优取向生长的MnAs外延层的磁性。具有平行于（001）GaAs的（1100）MnAs（“A型”）的样品显示不对称的磁滞回线和反常的矫顽场温度依赖性。我们将这些异常归因于与铁磁α-MnAs相共存的应变诱导反铁磁β-MnAs相的存在所产生的固有交换偏置效应。这些不寻常的影响消失，随着样品厚度的减少，这表明一种策略，用于抑制反铁磁β-MnAs相。
We have studied the magnetic properties of MnAs epilayers grown in two preferred orientations on (001) GaAs by molecular-beam epitaxy. Samples with the (1100) MnAs parallel to (001) GaAs (“type A”) show asymmetric hysteresis loops and an anomalous temperature dependence of the coercive field. We attribute these anomalies to intrinsic exchange biasing effects arising from the presence of a strain-induced antiferromagnetic β-MnAs phase that coexists with the ferromagnetic α-MnAs phase. These unusual effects vanish with decreasing sample thickness, suggesting a strategy for suppressing the antiferromagnetic β-MnAs phase.