Magnetic behavior of diluted lanthanoid-pnictide systems

We describe a new class of low-carrier-density magnetic materials based on lanthanide-substituted scandium and yttrium pnictides. In general, these III-V compounds have energy gaps in the vicinty of 1 eV, and like most of the lanthanide pnictides, form in the B1 (rocksalt) structure. Substitution of rare earths for Y or Sc to form solid solutions is readily achieved. For example, we have produced Gd_xY_1-xN by reactive magnetron cosputtering, and obtained epitaxial growth on sapphire substrates resulting in high-quality single-crystal thin films. These films exhibit moderately low carrier densities and high mobilities, and have interesting magnetic properties at low temperatures. In this paper we present a preliminary look at some of the properties of these materials.