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Professor of Physics Xuemei M. Cheng and Alums Co-Author Article, May 2023

July 12, 2023

Interfacial and Surface Magnetism in Epitaxial NiCo2O4(001)/MgAl2O4 Films

Authors: Corbyn Mellinger, Xiao Wang, Ph.D. '20, Arjun Subedi, Andy T. Clark, Ph.D. '22, Takashi Komesu, Richard Rosenberg, Peter Dowben, Xuemei Cheng, and Xiaoshan Xu

Source: Journal of Applied Physics, Volume: 133, Issue: 19, Article Number: 195301, DOI: 10.1063/5.0152539, May 2023

Type of Publication: Journal Article

Abstract: 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.

Xuemei M. Cheng is dean of graduate studies and professor of physics. 

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