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

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.

6 pages, 4 figures. New figure and text added to manuscript