Magneto-electric behaviors of La_(0.67-x)Nd_(x)Sr_(0.33)MnO_(3) system

The polycrystalline samples La_(0.67-x)Nd_(x)Sr_(0.33)MnO_(3)(x=0.1,0.2,0.3,0.4,0.5)were prepared by standard solid-state reaction method,and the M–T curves,electron spin resonance(ESR)curves,infrared spectra,Raman spectra,ρ–T curves and MR–T curves of the compounds above were measured.The results show that single phase can be obtained at different Nd substitution ratios,and with the increase in Nd doping,the magnetic structure of the system transforms from long-range ferro-magnetic order to spin cluster glass state and antiferro-magnetic state;and the phase separation appears in the samples with x=0.3 and 0.4.The transport property exhibits variation with the increase in Nd doping,and the electric behavior of the sample transforms(from metal state to insulator–metal transition,and then insulator state)is accompanied by colossal magnetoresistance(CMR)effect,which can be attributed to the different couplings of sublattices induced by Nd doping and the interface tun-neling effect related to the spin.