Publication date: Available online 12 November 2016
Source:Thin Solid Films
Author(s): Shwetha G. Bhat, P. S. Anil Kumar
Exchange bias (EB) in a single magnetic film has always been an intriguing subject to the researchers. But the quest for the origin of EB in Fe3 O4 films at temperatures, T3 O4 on (100) GaAs. Non-zero EB is observed to be retained even up to 553 O4 . Invariance of blocking temperature and the identical exponential nature of EB for different thickness of Fe3 O4 suggests the origin of EB to be similar in all the films. Variation of coercivity with temperature in our case supports the disorder driven magnetic interactions in Fe3 O4 films at TV , which is the Verwey transition of Fe3 O4 . Hence, the exchange bias is thought to exist between the intra-grain ferrimagnetic Fe3 O4 region and the antiferromagnetic grain boundary region. Reduced island sizes with lower defect area for higher thickness of Fe3 O4 further supports the claim of defect mediated exchange pinning in a thin film of single magnetic material, Fe3 O4 . In addition, training of exchange bias in Fe3 O4 films can be carried out similar to the films consisting of traditional ferromagnetic-antiferromagnetic layers.
Source:Thin Solid Films
Author(s): Shwetha G. Bhat, P. S. Anil Kumar