Strain induced super-paramagnetism in Cr2O3 in the ultra thin film limit

Abstract

ABSTRACTUltra thin films of chromia (Cr2O3), less than 3 nm thick, grown epitaxial on α-Al2O3 (sapphire), and are thus compressively strained in-plane. The resulting films show evidence of some magnetic ordering above the Néel temperature of chromia (307 K). The observed higher temperature hysteresis effect observed are very likely a strain effect, and not associated with the typical antiferromagnetic ordering expected of chromia.