Structural and magnetic properties of La/sub 1-x/Sr/sub x/CoO/sub 3/

The structural and the magnetic properties of polycrystalline La/sub 1-x/Sr/sub x/CoO/sub 3/ (LSCO) have been studied experimentally. The single LSCO phase in all the prepared samples were confirmed by the X-ray diffraction and X-ray photoelectron spectroscopy measurements. From the temperature dependence of inverse magnetic susceptibility, the Curie temperatures are found to be 147 K, 217 K, and 232 K for x=0.15,0.25, and 0.3, respectively. However, zero-field-cooled magnetization measurement reveals a spin-glass-like behavior for x=0.15. A neutron-diffraction study does not reveal the existence of an antiferromagnetic phase at low temperatures. It is thought that a more advanced magnetic model is required to elucidate the spin-glass behavior at low Sr concentrations.