Magnetic properties and transport properties of Nd_(0.67)Pb_(0.33)MnO_3 film

Using magnetron sputtering method,Nd_(0.67)Pb_(0.33)MnO_3 thin film was grown on(100)LaAlO_3 single- crystal substrates.The thin film was investigated by X-ray diffraction,superconducting quantum interference device and De four probed method.The results show that the thin film have a pseudo-cubic perovskite structure with the cell parameter a=3.846nm.The Curie temperature is 158K.Near the Curie temperature,the magnetic property shows a transition from ferromagnetic to paramagnetie.The electrical property indicates a transition from metal to semiconductor.Nd_(0.67)Pb_(0.33)MnO_3 thin film exhibit a characteristic spin glass state from zero-field cooled and field cooled magnetization curve,which is due to strain effects.The thin film has quite a distinctive magnetoresistance effect which is 28.5% near the Curie temperature when the magnetic field is 1T.Transport properties indicate that the resistivity satisfy model:ρ(T)=ρ0+ρ1T~2+ρ2T~5 when the temperature is below T_(MI) due to electron-electron scattering,the resistivity satisfy polarons model when the temperature is above T_(MI)ow- ing to the existence of the small polarons nearest hopping.