【摘要】 测量了La2 CuO4 掺Zn样品在不同降温速率下 (330K保温 0 5h ,然后分别以 6K h ,0 2K s的速度降到 8K)的直流磁化率和热电势 .实验结果表明 ,反铁磁温度TN 不随降温速率变化而变化 ,其直流磁化率也未受很大影响 .高温热电势弱的温度依赖关系表明为极化子气体的贡献 .热电势在转折温度Tdrop之下的快速降低是由于二维反铁磁涨落的贡献 .热电势在更低温度的拐点TS 与载流子的局域化有关 .降温速率变化时 ,Tdrop和TS 都有明显的变化 .Zn掺杂对Tdrop和TS 没有明显影响 ,但导致了更强的载流子局域化 .讨论了上述现象产生的物理图像更多还原

【Abstract】 We report on a study of the temperature dependence of thermoelectric power and DC susceptibility of Zn doped La 2CuO 4 throngh slow cooling and slow warming after quenching (6K/h,and 0.2K/s respectively).The antiferromagnetic (AF) transition temperature T N does not change with changing cooling rates and the dc susceptibility for La 2CuO 4 is not much affected.The high temperature thermopower is weakly temperature dependent,suggesting the hopping contribution of polarons.The rather rapid linear decrease in the thermopower below T drop is attributed to the contribution of the two dimensional AF fluctuations.The spinodal in thermopower at lower temperature is confirmed to be related with the localization of the charge carriers.The T drop and T S are obviously changed by changing cooling rates while they are not affected much by Zn doping.However,the Zn doping results in a stronger localization of charge carriers.In this paper,we discuss the physical origins related to above phenomena.更多还原