1304.2205 (Tuhin Maity et al.)

Spontaneous exchange bias in a nanocomposite of
BiFeO$_3$-Bi$_2$Fe$_4$O$_9$    [PDF]

Tuhin Maity, Sudipta Goswami, Dipten Bhattacharya, Gopes C. Das, Saibal Roy

We have observed a large as well as path-dependent spontaneous exchange bias (H$_{SEB}$) ($\sim$30-60 mT) in a nanocomposite of BiFeO$_3$-Bi$_2$Fe$_4$O$_9$ across 5-300 K when it is measured in an unmagnetized state following zero-field cooling and appropriate demagnetization. The path dependency yields a variation in the exchange bias depending on the sign of the starting field and the path followed in tracing the hysteresis loop. The asymmetry thus observed - $\Delta$H$_{SEB}$ - is found to be decreasing nonmonotonically across 5-300 K with a peak around 200 K. The $\Delta$H$_{SEB}$ together with large H$_{SEB}$ could have significant ramification in tuning the exchange bias driven effects and consequent applications.

View original: http://arxiv.org/abs/1304.2205