Li Qiuhang, Yuan Xueping, Xing Lei, Xu Mingxiang
Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096, China.
Department of Fundamental Courses, Nantong Polytechnic College, Nantong 226002, China.
Sci Rep. 2016 Jun 13;6:27712. doi: 10.1038/srep27712.
Polycrystalline layered perovskite Sr2CoO4 sample was synthesized by high temperature and high pressure method. The staircaselike behavior has been observed in the magnetization and resistivity versus field curves of Sr2CoO4 at low temperature. The main features of the steps can be obtained from the measured results: (i) the positions of the external magnetic field at which steps occur are varying in different measurement runs, (ii) the steps only appear at low temperature and disappear with a slight increase of the temperature, (iii) the steps are dependent on the temperature and field sweep rate. Based on the features of the magnetization and magneto-transport staircaselike behavior in Sr2CoO4, the unusual phenomenon can be ascribed to an avalanche of flipping domains in terms of the random field theory.
采用高温高压法合成了多晶层状钙钛矿Sr2CoO4样品。在低温下，Sr2CoO4的磁化强度和电阻率随磁场曲线中观察到了阶梯状行为。从测量结果可以得到这些阶梯的主要特征：(i) 出现阶梯的外部磁场位置在不同的测量过程中是变化的；(ii) 阶梯仅在低温下出现，随着温度略有升高而消失；(iii) 阶梯取决于温度和磁场扫描速率。基于Sr2CoO4中磁化和磁输运阶梯状行为的特征，根据随机场理论，这种异常现象可归因于翻转磁畴的雪崩。
