Exchange bias effect in Fe/LaAlO3: An interface induced effect.

The present work reports the appearance of the exchange bias (EB) effect at low temperatures in epitaxial Fe thin film deposited on single crystalline LaAlO 3 (001) substrate. The observed EB effect vanishes around 30 K indicating that it could be due to the formation of antiferromagnetic FeO layer at the interface between Fe and LaAlO 3 substrate. The EB in Fe/LaAlO 3 (001) is further substantiated by comparing the observations with polycrystalline Fe film deposited on silicon substrate, kept adjacent to LaAlO 3 substrate during the deposition. Magnetic microstructure measured by Kerr microscopy corroborates the structural data of Fe film i.e., cubic four-fold anisotropy and isotropic nature for Fe film deposited on LaAlO 3 and silicon substrates, respectively. Further, low temperature Kerr microscopy results reveal that the magnetization reversal process significantly gets modified due to the induced unidirectional anisotropy as a consequence of FeO layer formation at Fe/LaAlO 3 interface. • Magnetic microstructural evidence for the cubic anisotropy in Fe/LaAlO 3. • Appearance of exchange bias in epitaxial Fe/LaAlO 3 thin film. • Change in magnetization reversal due to induced unidirectional anisotropy. [ABSTRACT FROM AUTHOR]