Origin of magnetic anomalies in the spin glass system, La 0.85Sr0.15CoO3

The composition with x=0.15 in the spin glass regime (0⩽x⩽0.18) of the perovskite system, La1−xSrxCoO3, is investigated in detail to understand the unusual magnetic properties reported in the literature. AC susceptibility and field-cooled and zero-field-cooled magnetization measurements give sufficient evidence for compositional inhomogeneity as the origin of the magnetic anomalies. A well-defined spin glass behavior is obtained only for a highly homogeneous sample.