Phase Separation and Magnetoresistance in Nd_0.52Sr_0.48MnO₃

Polycrystalline Nd_0.52Sr_0.48MnO₃ ceramic is prepared by a Pechini process. Its electron spin resonance spectra, magnetic and transport properties have been investigated experimentally. At temperature above 270 K, the compound is paramagnetic insulator, while in temperature between 160 K and 270 K, the compound is separated into a paramagnetic insulator and a ferromagnetic metal coexisting state. Below 160 K, theferromagnetic phase coexists with an antiferromagnetic state, but the ferromagnetic phase remains to be dominant. This makes the compound exhibiting a metallic character even at temperature far below T_N.