Magnetic and electronic transport properties of Mn-doped silicon

Polycrystalline Si1−xMnx ( x = 0.005 , 0.01, and 0.015) samples were prepared by the arc-melting method. Powder x-ray diffraction analysis demonstrates that the light Mn doping does not change the crystalline structure of silicon. Magnetic studies reveal that the ferromagnetism can be developed in all Mn-doped samples and the Curie temperature ( T C ) increases with increasing Mn doping content x . The effective magnetic moments are 4.15, 4.05 μ B / Mn for the samples with x = 0.01 and 0.015, respectively. The undoped sample shows semiconducting behavior in the whole studied temperature range, whereas a metal–insulator transition can be observed near T C for all doped samples. The thermally activated conducting mechanism dominates the low temperature transport properties of the doped samples. The activation energy obtained from the fitting decreases monotonously with increasing x . In addition, the anomalous Hall effect below T C was observed from the magnetic field dependence of the Hall resistivity curves.