Mechanism of electrical conduction of Mn-doped β-FeSi2

In order to clarify the mechanism of electrical conduction of Mn-doped β-FeSi2 (Fe1−xMnxSi2), the Hall effect and electrical resistivity of Fe1−xMnxSi2 (0.01≦x≦0.10) have been measured in the temperature range between 80 and 300 K. The hole concentration of Fe1−xMnxSi2 at 300 K ranges from 8.9×1017 cm−3 for x=0.01 to 1.1×1019 cm−3 for x=0.10, which is almost proportional to the Mn doping concentration (x). The temperature dependence of electrical resistivity of Fe1−xMnxSi2 shows an S-like decay curve at high temperatures. It is concluded that this shape results from the drastic decrease of the mobility with increasing temperature. We present experimental evidence that explains the electrical conduction of Fe1−xMnxSi2 at high temperatures by the impurity scattering mechanism.