Magnetism in Si1−xMnx diluted magnetic semiconductor thin films

We have studied the electrical and magnetic properties of p-type semiconductor thin films of Si1−xMnx/Si (x=0.036 and 0.05) grown by molecular beam epitaxy. Experimental results reveal that the resistivity of the samples decreases gradually with increasing measurement temperature, which can be described well by Mott's variable-range-hopping model. All the samples exhibit the ferromagnetic ordering above room temperature. Among these samples, Si0.95Mn0.05 has a higher hole density and magnetization. This indicates an enhancement of hole-mediated ferromagnetic exchange interactions when the Mn-doping concentration is increased.