Exchange bias with Fe substitution in LaMnO_3

TL;DR

This paper investigates the exchange bias phenomenon in Fe-substituted LaMnO_3, revealing nanoscale ferromagnetic clusters embedded in a glassy magnetic matrix and analyzing their magnetic properties.

Contribution

It introduces the observation of exchange bias in LaMn_{0.7}Fe_{0.3}O_3 and characterizes the nanoscale ferromagnetic clusters responsible for this effect.

Findings

Ferromagnetic cluster size ~25 Å

Magnetic anisotropy of FM clusters is two orders higher

EB arises from FM clusters embedded in glassy magnetic host

Abstract

The exchange bias (EB) in LaMn_{0.7}Fe_{0.3}O_3 is observed by the negative shift and training effect of the hysteresis loops, while the sample was cooled in external magnetic field. The analysis of cooling field dependence of EB gives the size of the ferromagnetic (FM) cluster ~ 25 Angstrom, where the magnetic anisotropy of FM cluster is found two order of magnitude higher than the FM bulk manganites. We propose that the nanoscale FM clusters are embedded in the glassy magnetic host with EB at the FM/glassy magnetic interface.