Unidirectional anisotropy in NiO/Co and NiO/Ni₈₀Fe₂₀ layered structures

Abstract

NiO/Co and NiO/Ni₈₀Fe₂₀ bilayers were prepared at 293 K onto SiO₂/Si(111) and glass substrates using UHV RF/DC magnetron sputtering. Results on ex-situ magnetic measurements showed that the unidirectional anisotropy field is inversely proportional to the Co (Ni₈₀Fe₂₀) layer thickness. A maximal RT coupling energy for the NiO−Co and NiO−Py interface was estimated as 0.04 and 0.03 mJ/m², respectively, for the samples prepared onto SiO₂/Si(111) substrates. The above behaviour is consistent with greater interface roughness and/or interdiffusion for the samples prepared onto glass substrates.