庞磁电阻效应材料中的低温电阻率反常现象

发现在La1/3Nd1/3Ba1/3MnO3和La1/3Nd1/3Sr1/3MnO3材料中存在低温电阻率极小值现象·经曲线拟合分析后,认为其机理在于材料中存在类似于磁性杂质对传导电子自旋散射造成的近藤效应(KondoEffect),是出现局域磁有序的结果

Abnormal Electric Resistivity Behaviour of CMR Materials at Low Temperature

Intrinsic abnormal minimum electrical resistivity phenomenon at low temperature was observed in Perovskite like La 1/3 Nd 1/3 Ba 1/3 MnO 3 and La 1/3 Nd 1/3 Sr 1/3 MnO 3 Oxides with CMR effect. A theoretical analysis was proposed by a polynomial fitting method, assuming there exists conductive electron spin scattering from located magnetic moments at low temperature besides crystal lattice scattering and interaction between electrons. The phenomenon was identified with the logarithmic dependence of temperature aroused from Kondo like effect and local magnetic ordering. This significant phenomenon implys the complication of the interacting mechanisms in CMR material. The most reasonable explanation for the behaviour is that the partial breaking of the Mn 3+ -O-Mn 4+ electrical conductive bonds, led by the oxygen lattice defects created by component fluctuation during heat treatment, results in inductive diluted magnetic moments which play a equivalent role of magnetic impurity.