Local electronic structure and magnetic properties of LaMn0.5Co0.5O3 studied by x-ray absorption and magnetic circular dichroism spectroscopy

TL;DR

This study investigates the local electronic and magnetic properties of LaMn0.5Co0.5O3 using soft-x-ray spectroscopy, revealing valence states, magnetic alignments, and orbital moments that influence its magnetic behavior.

Contribution

It provides new insights into the valence states, magnetic alignments, and orbital moments of LaMn0.5Co0.5O3, highlighting the presence of high-spin Co^{2+}--Mn^{4+} states and large orbital moments.

Findings

Co^{2+}--Mn^{4+} valence state with high-spin configuration

Presence of low-spin Co^{3+} ions in samples with lower Curie temperatures

Large orbital moment of Co^{2+} ions indicating significant magnetocrystalline anisotropy

Abstract

We have studied the local electronic structure of LaMn0.5Co0.5O3 using soft-x-ray absorption spectroscopy at the Co-L_3,2 and Mn-L_3,2 edges. We found a high-spin Co^{2+}--Mn^{4+} valence state for samples with the optimal Curie temperature. We discovered that samples with lower Curie temperatures contain low-spin nonmagnetic Co^{3+} ions. Using soft-x-ray magnetic circular dichroism we established that the Co^{2+} and Mn^{4+} ions are ferromagnetically aligned. We revealed also that the Co^{2+} ions have a large orbital moment: m_orb/m_spin ~ 0.47. Together with model calculations, this suggests the presence of a large magnetocrystalline anisotropy in the material and predicts a non-trivial temperature dependence for the magnetic susceptibility.