Synthesis and Magnetic Properties of Perovskite ${rm La}_{{rm 1-x}}{rm Sr}_{rm x}{rm MnO}_{{3}}$ Nanoparticles

摘要

Perovskite nanoparticles ${rm La}_{{rm 1-x}}{rm Sr}_{{rm x}}{rm MnO}_{{rm 3}}$ were successfully synthesized by modified sol-gel method. Their structure and magnetic properties were systematically investigated in dependence on doped Sr ratio $x$ . The structure was investigated by X-ray diffraction and showed a slight change, but magnetic properties varied strongly with changing $x$ . Magnetic properties of samples studied by physical property measurement system show spin-glass behavior with Curie temperature and blocking temperatures above room temperature. The blocking temperature as well as Curie temperature varies by changing $x$ . At room temperature, the samples show superparamagnetic properties with high saturation magnetization $M_{{S}}$ up to 87 emu/g, which strongly depends on the doped Sr ratio $x$ .