Magnetic properties of the layered III-VI diluted magnetic semiconductor Ga1$-$xFexTe

Magnetic properties of single crystalline Ga1-xFexTe (x $=$ 0.05) have been measured. GaTe and related layered III-VI semiconductors exhibit a rich collection of important properties for THz generation and detection. The magnetization versus field for an x $=$ 0.05 sample deviates from the linear response seen previously in Ga1-xMnxSe and Ga1-xMnxS and reaches a maximum of 0.68 emu/g at 2 K in 7 T. The magnetization of Ga1-xFexTe saturates rapidly even at room temperature where the magnetization reaches 50{\%} of saturation in a field of only 0.2 T. In 0.1 T at temperatures between 50 and 400 K, the magnetization drops to a roughly constant 0.22 emu/g. In 0 T, the magnetization drops to zero with no hysteresis present. The data is consistent with Van-Vleck paramagnetism combined with a pronounced crystalline anisotropy, which is similar to that observed for Ga1$-$xFexSe. Neither the broad thermal hysteresis observed from 100-300 K in In1$-$xMnxSe nor the spin-glass behavior observed around 10.9 K in Ga1$-$xMnxS are observed in Ga1$-$xFexTe. Single crystal x-ray diffraction data yield a rhombohedral space group bearing hexagonal axes, namely R3c. The unit cell dimensions were a $=$ 5.01 A, b $=$ 5.01 A, and c $=$ 17.02 A, with alpha $=$ 90*, Beta $=$ 90*, and gamma $=$ 120* giving a unit cell volume of 369 A\textasciicircum 3.