Coupled magnetic and elastic properties in LaPr(CaSr)MnO manganites

TL;DR

This study explores how magnetic and elastic properties are interconnected in LaPr(CaSr)MnO manganites, revealing magneto-elastic coupling and phase behavior changes with composition and temperature.

Contribution

It demonstrates the influence of material structure on magnetic properties and provides experimental evidence of magneto-elastic coupling in phase-separated manganites.

Findings

Magneto-elastic coupling observed below 100 K.

Transition from phase separation to homogeneous ferromagnetism with Sr doping.

Lattice contraction correlates with increased magnetization.

Abstract

We investigate a series of manganese oxides, the La0.225Pr0.4(Ca1-xSrx)0.375MnO3 system. The x = 0 sample is a prototype compound for the study of phase separation in manganites, where ferromagnetic and charge ordered antiferromagnetic phases coexist. Replacing Ca2+ by Sr2+ gradually turns the system into a homogeneous ferromagnet. Our results show that the material structure plays a major role in the observed magnetic properties. On cooling, at temperatures below 100 K, a strong contraction of the lattice is followed by an increase in the magnetization. This is observed both through thermal expansion and magnetostriction measurements, providing distinct evidence of magneto-elastic coupling in these phase separated compounds.