Magnetic Metastability driven Anomalous Hall Effect in Fe_(x)TaS₂

We report here the observation of robust thermoremanent magnetization (TRM) in Fe-intercalated TaS$_2$ single crystal Fe$_{x}$TaS$_2$, which develops upon cooling under a moderate magnetic field of 500 Oe or higher. The thermoremanence is found to exist in a zero magnetic field up to a temperature as high as 160 K, which is well above the ferromagnetic Curie point ($T_C =$ 90 K) of the sample. The TRM in this compound can be traced back to the strong Ising character and the quasi-two-dimensional nature of the spins. The analysis of the magnetization data indicates the presence of short-range magnetic correlation in the form of a Griffiths singularity above $T_C$ to a temperature as high as 2$T_C$. The TRM is further manifested in the form of a large anomalous Hall effect (AHE) in zero magnetic field. In contrast to TRM, which exists well above $T_C$, the thermoremanent Hall effect vanishes as soon as the sample is heated above $T_C$. This may be an indication that a long-range ordered phase is essential for the emergence of AHE.