Half-Metallicity of LSMO

TL;DR

This study uses advanced calculations to explore how doping and structural changes in LSMO influence its electronic and magnetic properties, revealing conditions for half-metallicity and charge ordering.

Contribution

It provides a detailed theoretical analysis of the effects of Sr doping, magnetic structure, and lattice distortions on the electronic states of LSMO, highlighting the emergence of half-metallicity.

Findings

Half-metallic state occurs with Mn$^{3+}$ configuration.

Mn$^{4+}$ state results in metallic behavior with low spin polarization.

Charge ordering with Mn$^{3+}$/Mn$^{4+}$ planes minimizes energy.

Abstract

Self-interaction corrected local spin density approximation calculations were performed for La$_{(1-x)}$Sr$_x$MnO$_3$ (LSMO) ($0.0<x<0.5$). The influence and inter-relationship of Sr doping, magnetic structure, O displacements and phase segregation on the Mn charge state were studied. A half-metallic state was obtained for LSMO with manganese configuration Mn$^{3+}$, whilst Mn$^{4+}$ gave rise to a metallic state with a negligible spin polarisation at the Fermi level. Elongating the MnO$_6$ octahedron led to a static mixed valence Mn$^{3+}$/Mn$^{4+}$ configuration. In the mixed valence state the total energy was minimized by an ordered array of Mn$^{4+}$ and Mn$^{3+}$ MnO$_2$ planes which showed charge ordered stripes.