Tuning the spontaneous exchange bias effect in La1.5Sr0.5CoMnO6 with sintering temperature

TL;DR

This study explores how sintering temperature affects the microstructure and enhances the spontaneous exchange bias effect in La1.5Sr0.5CoMnO6 by altering grain size and magnetic interface interactions.

Contribution

It demonstrates the tunability of exchange bias in La1.5Sr0.5CoMnO6 through controlled sintering, linking microstructure to magnetic properties.

Findings

Exchange bias increases with grain size.

Higher sintering temperatures lead to larger grains.

Microstructural changes influence magnetic interface interactions.

Abstract

Here, we present a study of the influence of microstructure on the magnetic properties of polycrystalline samples of the La1.5Sr0.5CoMnO6 double perovskite, with primary attention to the spontaneous exchange bias effect, a fascinating recently discovered phenomena for which some materials exhibit unidirectional magnetic anisotropy after being cooled in zero magnetic fields. By sintering La1.5Sr0.5CoMnO6 at different temperatures, we obtained samples with distinct average grain sizes, ranging from 1.54 to 6.65 mu_m. A detailed investigation of the material's structural, morphologic, electronic, and magnetic properties using X-ray powder diffraction, powder neutron diffraction, X-ray absorption near edge structure spectroscopy, scanning electron microscopy, and AC and DC magnetometry has revealed a systematic enhancement of the exchange bias effect with increasing the average grain size. This evolution is discussed in terms of changes in the material's porosity and grain morphology and its influence on the exchange couplings at the magnetic interfaces.