Magnetoresistance of a Bulk Sample of FeSi

The magnetoresistance of a well-characterized bulk FeSi sample has been studied. It is shown that after some complicated behavior at temperatures below 6 K, the magnetoresistance of FeSi, becomes a regular function of temperature and magnetic field. Then, the magnetoresistance passes a maximum at about 12 K and gradually decreases, approaching slightly negative values and then zero. Thus, the observations suggest the existence of the negative component of magnetoresistance, which appears at about 12 K and finally defines the negative values of both transverse and longitudinal magnetoresistance of FeSi at high temperatures. The n-egative component of magnetoresistance may be related to the topological features of the chiral structure of FeSi.