Study on the thermopower and magnetic properties of Zn doped La2CuO4
Zn掺杂La2CuO4热电势和磁化率研究

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.