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用固相反应法制备La0.5Sm0.2Sr0.3MnO3/x(Sb2O3)(x=0.00,0.02,0.04,0.05,0.075,0.10,0.15)系列样品,通过X射线衍射(XRD)谱、电阻率-温度(ρ～T)曲线、ρ～T拟合曲线、磁电阻-温度(MR～T)曲线,研究了该体系的电输运性质及MR的温度稳定性.所有样品的电输运性质都表现出绝缘体-金属相变,相变温度很高(312K)且基本保持不变,随Sb2O3复合量增大,电阻率迅速增大,类金属导电可以用ρ=ρ0+AT2公式拟合,表明导电机制是电子-电子相互作用,x=0.075的样品,在200～320K温区磁电阻基本保持不变,MR的温度稳定性是晶界引起的隧穿磁电阻与钙钛矿颗粒体相本征磁电阻竞争的结果.
The samples of La0.5Sm0.2Sr0.3MnO3 / x (Sb2O3) (x = 0.00,0.02,0.04,0.05,0.075,0.10,0.15) were prepared by solid-state reaction and characterized by X-ray diffraction (XRD) (Ρ ~ T) curve, ρ ~ T fitting curve and MR-T curve, the electrical transport properties and MR temperature stability of the system were studied.The electric transport properties of all samples The results show that the phase transition temperature is high (312K) and remains unchanged. With the increase of Sb2O3 content, the resistivity increases rapidly. The metal-like conductivity can be fitted by ρ = ρ0 + AT2 formula The conduction mechanism is electron-electron interaction, x = 0.075 samples, the magnetic resistance in the temperature range of 200 ~ 320K remains basically unchanged, the temperature stability of MR is grain boundary caused by the tunneling magnetic resistance and perovskite particles phase intrinsic Magnetoresistive competition results.