Magnetic characteristics of epitaxial Ge(Mn,Fe) diluted films - a new room temperature magnetic semiconductor?

We prepare 100 nm thick, epitaxial Ge100-(x+y)(MnxFey) diluted films with Mn and Fe concentrations of several at% using a layer-by-layer deposition scheme at elevated temperature. We measure saturation magnetization m(s) versus temperature curves for a variety of (x,y) combinations and find for fixed temperatures a non-trivial dependence of ms on x and y. Within a certain window in the (x,y) parameter space Ge100-(x+y)(Mn-x,Fe-y) exhibits a Curie temperature of 350 K and m(s) approximate to 10 emu/cm(2) at room temperature. (C) 2004 Elsevier B.V. All rights reserved