Magnetic interactions in Ge1−xEuxTe semiconductors: random distribution of magnetic Eu ions versus spinodal decompositions

Abstract We present the studies of structural, magnetotransport, and magnetic properties of Ge 1− x Eu x Te bulk crystals with the chemical composition, x , changing from 0.008 to 0.025. For the samples with x > 0.015 the sample synthesis leads to formation of Ge 1− x Eu x Te spinodal decompositions with a broad range of chemical contents. The presence of Ge 1− x Eu x Te spinodal decompositions is responsible for the antiferromagnetic order in our samples with x > 0.015. For the samples with x < 0.015 the structural characterization shows no evidence for clusters, the samples are paramagnetic, but the analysis of the results of magnetic measurements indicates deviations from the random distribution of Eu ions.