Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA.
Phys Rev Lett. 2012 Sep 14;109(11):117201. doi: 10.1103/PhysRevLett.109.117201. Epub 2012 Sep 10.
A spin reorientation accompanying the temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) phase transition is reported in strained epitaxial FeRh thin films. (57)Fe conversion electron Mössbauer spectrometry showed that the Fe moments have different orientations in FeRh grown on thick single-crystalline MgO and in FeRh grown on ion-beam-assist-deposited (IBAD) MgO. It was also observed, in both samples, that the Fe moments switch orientations at the AFM to FM phase transition. Perpendicular anisotropy was evidenced in the AFM phase of the film grown on IBAD MgO and in the FM phase of that grown on regular MgO. Density-functional theory calculations enabled this spin-reorientation transition to be accurately reproduced for both FeRh films across the AFM-FM phase transition and show that these results are due to differences in strain.
应变外延 FeRh 薄膜中存在伴随温度诱导反铁磁 (AFM) 到铁磁 (FM) 相变的自旋重取向。(57)Fe 转换电子穆斯堡尔谱表明，在厚单晶 MgO 上生长的 FeRh 和在离子束辅助沉积 (IBAD) MgO 上生长的 FeRh 中，Fe 磁矩具有不同的取向。在这两种样品中，都观察到 Fe 磁矩在 AFM 到 FM 相变时发生了取向的切换。在 IBAD MgO 上生长的薄膜的 AFM 相中存在垂直各向异性，而在常规 MgO 上生长的薄膜的 FM 相中存在垂直各向异性。密度泛函理论计算能够准确再现两种 FeRh 薄膜在 AFM-FM 相变过程中的自旋重取向转变，并表明这些结果归因于应变的差异。
