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.
Categories: cond-mat.str-el cond-mat.mtrl-sci