Magnetic interactions in Ge1-xCrxTe semimagnetic semiconductors

作者：Kilanski L^*; Podgorni A; Dobrowolski W; Gorska M; Reszka A; Kowalski B J; Domukhovski V; Szczerbakow A; Szalowski K; Anderson J R; Butch N P; Slynko V E; Slynko E I

来源：Journal of Applied Physics, 2012, 112(12): 123909.

DOI：10.1063/1.4769795

We present the studies of magnetic properties of Ge1-xCrxTe diluted magnetic semiconductor with changeable chemical composition 0.016 <= x <= 0.061. A spin-glass state (at T <= 35 K) for x=0.016 and 0.025 and a ferromagnetic phase (at T < 60 K) for x >= 0.030 are observed. The long range carrier-mediated magnetic interactions are found to be responsible for the observed magnetic ordering for x < 0.045, while for x >= 0.045 the spinodal decomposition of Cr ions leads to a maximum and decrease of the Curie temperature, T-C, with increasing x. The calculations based on spin waves model are able to reproduce the observed magnetic properties at a homogeneous limit of Cr alloying, e. g., x < 0.04, and prove that carrier mediated Ruderman-Kittel-Kasuya-Yosida interaction is responsible for the observed magnetic states. The value of the Cr-hole exchange integral, J(pd), estimated via fitting of the experimental results with the theoretical model, is in the limits 0.77...0.88 eV.

• 出版日期2012-12-15