Spin states and phase separation in La_{1-x}Sr_{x}CoO_3 (x=0.15, 0.25, 0.35) films: optical, magneto-optical and magneto-transport studies

TL;DR

This study investigates the optical, magneto-optical, and transport properties of La$_{1-x}$Sr$_{x}$CoO$_3$ films, revealing spin state transitions and phase separation effects influenced by Sr doping.

Contribution

It provides new insights into the spin states and phase separation phenomena in La$_{1-x}$Sr$_{x}$CoO$_3$ films through comprehensive optical and magneto-transport measurements.

Findings

Identification of Co$^{3+}$ spin state transition from low-spin to intermediate-spin.

Observation of orbital ordering in Co$^{3+}$ ions.

Evidence of phase separation influenced by Sr doping.

Abstract

Optical absorption and transverse Kerr effect spectra, resistivity and magnetoresistance of La$_{1-x}$Sr$_{x}$CoO$_3$ ($x=0.15, 0.25, 0.35$) films have been studied. The temperature dependencies of the optical and magneto-optical properties of the films exhibit features, which can be attributed to the transition of the Co$^{3+}$ ions from the low-spin state (S=0) to the intermediate-spin state (S=1) and to orbital ordering of the Co$^{3+}$ ions in the latter state. The evolution of the properties influenced by doping with Sr is interpreted on the basis of the phase separation model.