Exchange bias effect and intragranular magnetoresistance in Nd$_{0.84}Sr_{0.16}CoO_3

TL;DR

This study investigates the exchange bias effect and intragranular magnetoresistance in polycrystalline Nd_{0.84}Sr_{0.16}CoO_3, revealing significant magnetic phenomena linked to its nanostructure.

Contribution

It reports the observation of exchange bias and magnetoresistance effects in Nd_{0.84}Sr_{0.16}CoO_3 and analyzes their training effects using established models.

Findings

Strong exchange bias observed in magnetoresistance curves

Training effect decreases exchange bias with successive field cycles

Time dependence in magnetoresistance linked to nanostructure

Abstract

Electrical transport properties as a function of magnetic field and time have been investigated in polycrystalline, Nd_{0.84}Sr_{0.16}CoO_3. 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 magnetic hysteresis loop. 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. Training effect could be analysed by the successful models. The EB effect, MR and a considerable time dependence in MR are attributed to the intrinsic nanostructure giving rise to the varieties of magnetic interfaces in the grain interior.