Magneto-transport and optical properties of diluted magnetic semiconductor Ga1−xMnxSb

We have studied magneto-transport and optical properties of Ga
_1-x
Mn
_x
Sb crystals (x = 0.01, 0.02, 0.03 and 0.04) grown by horizontal Bridgman method. Negative magnetoresistance and anomalous Hall effect have been observed below 10 K. Temperature dependence of magnetization measurement shows a magnetic ordering below 10 K which could arise from Ga
_1-x
Mn
_x
Sb alloy formation. Also, saturation in magnetization observed even at room temperature suggests the existence of MnSb clusters. Reduction in band gap is observed with increasing Mn concentration in the crystals. Temperature dependence of band gap follows Bose-Einstein's model.