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 mu(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. (c) 2006 Elsevier Ltd. All rights reserved.