【作者】 马永青； 宋文海； 戴建明； 张瑞丽； 杨杰； 杜家驹； 孙玉平；

【Author】 MA Yongqing SONG Wenhai DAI Jianming ZHANG Ruili YANG Jie DU Jiaju SUN Yuping Institute of Solid State Physics,The Chinese Academy of Sciences,Hefei 230031

【机构】 中国科学院固体物理研究所；

【摘要】 用内耗的方法测量了钙钛矿结构锰氧化物 La_0．67Ca_0．33MnO₃的内耗温度曲线 Q^-1（T）．在260,222和105 K 温度处分别出现内耗峰．分析表明105 K 处的内耗峰与铁磁态中的电子相分离有关．222 K 处的内耗峰由两个次峰构成,峰温分别为222和234 K,并具有弛豫特征,与绝缘畴和金属畴的相对移动有关．它们的激活能以及指数前因子分别为0．32 eV, 2．0×10^-12s 和0．38 eV．2．5×10^-13s．更多还原

【Abstract】 Internal friction measurement of perovskite manganite La_0.67Ca_0.33MnO₃ shows that there are three peaks in the spectra of internal friction Q^-1（T）at temperatures 260 K,222 K and 105 K,respectively.It is concluded,that the peak at 105 K is related to the electronic phase separation in ferromagnetic region.The broad peak around 222 K is composed of two sub-peaks located at 222 K and 234 K.This broad peak is of the characteristic of relaxation originating from the thermally activated motion of insulating and conduction domains.The activation energy and the relaxation time at infinite temperature are determined as 0.32 eV,2.0×10^-12s for 222 K subpeak and 0.38 eV, 2.5x10^-13s for 234 K subpeak,respectively.更多还原