Neutron scattering study of magnetic phase separation in nanocrystalline La$_{5/8}$Ca$_{3/8}$MnO$_3$

TL;DR

This study uses neutron scattering to investigate how strain influences magnetic phase separation in nanocrystalline La$_{5/8}$Ca$_{3/8}$MnO$_3$, revealing reversible stabilization of antiferromagnetic domains within a ferromagnetic matrix.

Contribution

It demonstrates that strain can be reversibly frozen into the lattice to control magnetic phase separation in CMR manganites, providing a new method to explore spin properties.

Findings

Strain stabilizes antiferromagnetic domains within ferromagnetic La$_{5/8}$Ca$_{3/8}$MnO$_3$.

Magnetic neutron diffraction reveals tunable phase separation.

Potential for enhanced CMR via intergrain spin tunnel junctions.

Abstract

We demonstrate that magnetic phase separation and competing spin order in the colossal magnetoresistive (CMR) manganites can be directly explored via tuning strain in bulk samples of nanocrystalline La$_{1-x}$Ca$_x$MnO$_3$. Our results show that strain can be reversibly frozen into the lattice in order to stabilize coexisting antiferromagnetic domains within the nominally ferromagnetic metallic state of La$_{5/8}$Ca$_{3/8}$MnO$_3$. The measurement of tunable phase separation via magnetic neutron powder diffraction presents a direct route of exploring the correlated spin properties of phase separated charge/magnetic order in highly strained CMR materials and opens a potential avenue for realizing intergrain spin tunnel junction networks with enhanced CMR behavior in a chemically homogeneous material.