Large coercivity and exchange bias in [Fe1-δ(FeO)δ]x(TiO2)1-x granular films.

Authors :: Cheng, Y. H.
Zhang, X. H.
Li, L. Y.
Wang, C. H.
Luo, X. G.
Liu, Hui
Wang, W. H.
Zheng, R. K.
Source :: Applied Physics Letters; 5/13/2013, Vol. 102 Issue 19, p192403, 4p, 1 Black and White Photograph, 5 Graphs
Publication Year :: 2013
Abstract: [Fe1-δ(FeO)δ]x(TiO2)1-x (0≤δ≤0.91, 0.34≤x≤0.54) granular films were fabricated by magnetron sputtering. Large coercivity (HC = 10.5 kOe) and exchange-bias-field (HE = 6.5 kOe) at 5 K were found in the film with δ=0.84 and x = 0.48. AC susceptibility measurements exhibit a frequency (f) dependent peak Tf in the in-phase susceptibility curve. The fitting of the relation of Tf vs f with both the Vogel-Fulcher law and critical slowing down theory indicate that the evident enhancement of the HC and HE can be qualitatively ascribed to the existence of cluster-spin glass state. The results may help to deeply understand the origin of exchange bias and related effects. [ABSTRACT FROM AUTHOR]