Magnetic and transport properties of perovskite La067Pb033MnO3

Abstract

Singlephase polycrystalline samples of La067Pb033MnO3 were prepared by conventional solidstate reaction method. The crystal structure and magnetic and transport properties are investigated. The structure revealed by the room temperature xray powder diffraction is rhombohedral(R3C), and the Curie temperature is very close to TMI(=360K). At the Curie point, the magnetic properties show the transition from ferromagnetic to paramagnetic, and the conductivity changes from metal to semiconducting. The resistivity decreases with increasing magnetic field. Magnetoresistance reaches a maximum at the Curie point. The maximum magnetoresistance is 14\^5% at H=1\^2MA/m, and 9% at H=0\^6MA/m. The transport results show that the transport data satisfy ρ(T)=ρ0+ρT2.5 for TTMI. This phenomenon is due to the magoncarrier scattering.