Interfacial and surface magnetism in epitaxial NiCo2O4(001)/MgAl2O4 films

NiCo2O4 (NCO) films grown on MgAl2O4 (001) substrates have been studied using magnetometry and x-ray magnetic circular dichroism based absorption spectroscopy spin-polarized inverse photoemission with various thicknesses down to 1.6 nm. The behavior can be understood in terms of a layer optimal NCO an interfacial (1.2 ± 0.1 nm), small canting magnetization at the surface. thickness dependence described by finite-scaling theory critical exponent consistent high perpendicular anisotropy. couples antiferromagnetically layer, generating exchange-spring styled hysteresis thinnest films. non-optimal measurement-speed-dependent properties suggest substantial diffusion.