Heat-induced antiferromagnetic coupling in multilayers with ZnSe spacers
Heat-induced antiferromagnetic coupling in multilayers with ZnSe spacers
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DOI：
10.1103/physrevb.60.4082
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发表时间：
1999-08
影响因子：
3.7
通讯作者：
P. Walser;M. Hunziker;T. Speck;M. Landolt
中科院分区：
文献类型：
--
作者：
P. Walser;M. Hunziker;T. Speck;M. Landolt
由非晶半导体间隔物分隔的两个铁磁膜跨间隔物层交换耦合。耦合是可逆的温度依赖性与正的温度系数。作为间隔材料，我们使用非晶ZnSe，这是一种化合物半导体，并发现热致反铁磁耦合在惊人的相似性，非晶硅和锗。在间隔层厚度为18 ~ 22 μ A的Fe/aZnSe/Fe三层膜中，耦合是反铁磁的，具有正的温度系数。在22 \AA{}和25 \AA{}之间的稍大的厚度，我们发现一个可逆的转变，从铁磁耦合在低温下的反铁磁耦合在较高的温度加热后。我们讨论了可逆的热诱导的有效交换耦合的费米能附近的带隙中的局域缺陷态。
Two ferromagnetic films separated by an amorphous semiconducting spacer are exchange coupled across the spacer layer. The coupling is reversibly temperature dependent with a positive temperature coefficient. As spacer material we use amorphous ZnSe which is a compound semiconductor and find heat-induced antiferromagnetic coupling in striking similarity to amorphous Si and Ge. In an Fe/$a$-ZnSe/Fe trilayer with spacer thickness between 18 \AA{} and 22 \AA{} the coupling is antiferromagnetic with a positive temperature coefficient. At slightly larger thicknesses between 22 \AA{} and 25 \AA{} we find a reversible transition from ferromagnetic coupling at low temperatures to antiferromagnetic coupling at higher temperatures upon heating. We discuss the reversibly heat-induced effective exchange coupling in terms of localized defect states in the band gap in the vicinity of the Fermi energy.