Magnetic measurements on the III-VI diluted magnetic semiconductor Ga1-xMnxSe

We have investigated the magnetic properties of Ga1-xMnxSe, which represent a new class of diluted magnetic semiconductors based on a III-VI semicondu ctor. These are layered materials; however the local environment is tetrahe dral as in the II-VI materials. In contrast to the II-VI semiconductors, th e Mn substitutional atoms have direct bonds to three Se atoms and to either a Ga or Mn atom. This leads to a complex temperature dependent magnetizati on. In fields of 100 G and below, a broad peak is observed in the magnetiza tion centered at 160 K. In addition, a sharp change in magnetization is obs erved at 119 K. In a field of 100 G, the peak has a magnitude of 3 x 10(-5) emu/g above the background of 7 x 10(-5) emu/g. With increasing magnetic f ields, these features are broadened which is suggestive of some type of sho rt-range antiferromagnetic ordering. At 5 K we observe a magnetization whic h increases linearly with field up to 6 T similar to the Van Vleck paramagn etic behavior observed in the Fe substituted LI-VI semiconductors. (C) 1998 American Institute of Physics.