Preparation of Anomalous Magnetoresistance and Transport Properties of Itinerant Ferromagnet Fe 1– x Co x Si

DC magnetization, electrical transport, and magnetoresistance (MR) measurements of Fe 1– x Co x Si single crystals with $x \approx $ 0.7–0.3 are reported. Fe 1– x Co x Si series presents a typical Stoner band excitation characteristic in the field-dependent magnetization profile. Co-doping ( x > 0.3) in the Fe 1– x Co x Si compound shows a semiconductor–to–metal transition. Enhanced positive MR has been observed when $\sim$ 1/3 of the Fe was substituted with Co, which suggests that the spin density of states in the minor band (semiconductor characteristic) dominates the electronic properties.