Spin-glass behavior and anomalous magnetoresistance in ferromagnetic Ge_(1-x)Fe_xTe epilayer

摘要

We report that the Ge_(1-x)Fe_xTe thin film exhibits spin-glass behavior when the Fe concentration increases to 0.08. A large bifurcation between the zero-field cooling and field cooling temperature-dependent magnetization was observed. The hysteresis loops after zero-field cooling and field cooling show an exchange bias effect. A time-dependent thermoremanent magnetization follows power-law decay, which confirms the existence of spin glass. The anomalous magnetotranport properties present a further evidence for spin-glass behavior and give a freezing temperature T_g～5K in the Ge_(0.92)Fe_(0.08)Te thin film.