Finite-Size Effects and Uncompensated Magnetization in Thin Antiferromagnetic CoO Layers

Abstract

Finite-size effects in CoO, an antiferromagnetic insulator with localized moments, have been observed in CoO/Si${\mathrm{O}}_{2}$ multilayers. The N\'eel temperatures of the CoO layers, as determined by dc susceptibility measurements, show a finite-size scaling relation with a shift exponent $\ensuremath{\lambda}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.55\ifmmode\pm\else\textpm\fi{}0.05$. Increased magnetization with an oscillation in magnitude, due to uncompensated antiferromagnetic layers, has also been observed.