Abstract. Electrical transport properties as a function of magnetic field and time have been investigated in polycrystalline, Nd_0.84Sr_0.16CoO₃. A strong exchange bias (EB) effect is observed associated with the fairly large intragranular magnetoresistance (MR). The EB effect observed in the MR curve is compared with the EB effect manifested in the magnetic hysteresis loop. A training effect, described as the decrease of EB effect when the sample is successively field cycled at a particular temperature, has been observed in the shift of the MR curve. The training effect could be analyzed by successful models. The EB effect, MR and a considerable time dependence in MR are attributed to the intrinsic nanostructure giving rise to varieties of magnetic interfaces in the grain interior.

Print publication: Issue 48 (2 December 2009)
Received 25 August 2009, in final form 8 October 2009
Published 6 November 2009