Microhardness as a function of Fe concentration in Gal−xFexSb, a III–V diluted magnetic semiconductor

The Vickers microhardness (MH), Hv of Gal−xFexSb, a new III–V diluted magnetic semiconductor is measured as a function of Fe concentration, x (0⩽x⩽0.0075) at room temperature. The substitution of Fe for Ga changes the MH and makes the material harder with increasing Fe concentration. This is due to solid solution hardening. Here, we discuss the interpretation of our results, in respect of those reported for Gal−xMnxSb and Gal−xInxAs on the basis of a change of the lattice parameter obeying the Vegardʹs law. On the basis of these results, it has also been shown that the change in Vickers MH with increasing alloying is perhaps much better explained by considering the change of volume due to a change of lattice parameter with alloying rather than that due to a change in chemical covalent bonding length.