Interfacial and surface magnetism in epitaxial NiCo2O4(001)/MgAl2O4 films
Interfacial and surface magnetism in epitaxial NiCo2O4(001)/MgAl2O4 films
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DOI：
10.1063/5.0152539
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发表时间：
2023-02
影响因子：
3.2
通讯作者：
Corbyn Mellinger;Xiao Wang;A. Subedi;Andy T. Clark;T. Komesu;R. Rosenberg;P. Dowben;Xuemei M. Cheng;Xiaoshan Xu
中科院分区：
文献类型：
--
作者：
Corbyn Mellinger;Xiao Wang;A. Subedi;Andy T. Clark;T. Komesu;R. Rosenberg;P. Dowben;Xuemei M. Cheng;Xiaoshan Xu
利用磁性测量和基于x射线吸收谱和自旋极化逆光电发射谱的x射线磁圆二色性研究了MgAl2O4（001）衬底上生长的不同厚度的NiCo2O4（NCO）薄膜，最小厚度为1.6nm。磁性行为可以用最佳NCO层和界面层（1.2 ± 0.1 nm）来理解，表面有一个小的磁化倾斜。最佳层的厚度依赖性可以用有限标度理论描述，其临界指数与高垂直磁各向异性相一致。界面层反铁磁耦合到最佳层，在最薄的薄膜中产生交换弹簧风格的磁滞。非最佳和测量速度依赖的界面层的磁性能表明大量的界面扩散。
NiCo2O4 (NCO) films grown on MgAl2O4 (001) substrates have been studied using magnetometry and x-ray magnetic circular dichroism based on x-ray absorption spectroscopy and spin-polarized inverse photoemission spectroscopy with various thicknesses down to 1.6 nm. The magnetic behavior can be understood in terms of a layer of optimal NCO and an interfacial layer (1.2 ± 0.1 nm), with a small canting of magnetization at the surface. The thickness dependence of the optimal layer can be described by the finite-scaling theory with a critical exponent consistent with the high perpendicular magnetic anisotropy. The interfacial layer couples antiferromagnetically to the optimal layer, generating exchange-spring styled magnetic hysteresis in the thinnest films. The non-optimal and measurement-speed-dependent magnetic properties of the interfacial layer suggest substantial interfacial diffusion.