Ferromagnetic-like behavior of Bi0.9La0.1FeO3-KBr nanocomposites

TL;DR

This study reveals that Bi0.9La0.1FeO3-KBr nanocomposites exhibit ferromagnetic-like behavior at higher KBr fractions, likely due to magneto-ionic coupling, a phenomenon not observed in pure BLFO ceramics.

Contribution

The paper demonstrates the emergence of ferromagnetic-like hysteresis in BLFO-KBr nanocomposites above 15% KBr, highlighting a novel magneto-ionic coupling mechanism.

Findings

Ferromagnetic-like hysteresis appears above 15% KBr in nanocomposites.

Remanent magnetization is approximately 0.14 emu/g.

Coercive field is about 1.8 Tesla at room temperature.

Abstract

We studied magnetostatic response of the Bi0.9La0.1FeO3-KBr composites (BLFO-KBr) consisting of nanosized (about 100 nm) ferrite Bi0.9La0.1FeO3 (BLFO) conjugated with fine grinded ionic conducting KBr. When the fraction of KBr is rather small (less than 15 wt percent) the magnetic response of the composite is very weak and similar to that observed for the BLFO (pure KBr matrix without Bi1-xLaxFeO3 has no magnetic response as anticipated). However, when the fraction of KBr increases above 15percent, the magnetic response of the composite changes substantially and the field dependence of magnetization reveals ferromagnetic-like hysteresis loop with a remanent magnetization about 0.14 emu/g and coercive field about 1.8 Tesla (at room temperature). Nothing similar to the ferromagnetic-like hysteresis loop can be observed in BLFO ceramics, which magnetization quasi linearly increases with magnetic field. Different physical mechanisms were considered to explain the unusual experimental results for BLFO-KBr nanocomposites, but only those among them, which are highly sensitive to the interaction of antiferromagnetic Bi0.9La0.1FeO3 with ionic conductor KBr, can be relevant. An appropriate mechanism turned out to be ferro-magneto-ionic coupling.