Neutron scattering studies of Cd_1-xMn_xTe (invited)

The diluted magnetic ("semimagnetic") semiconductor Cd _1-xMn_xTe reveals intriguing spin glass properties. In this paper, the results of neutron scattering studies of Cd_1-xMn _xTe are presented. The low-temperature spin correlations have been studied for several single crystal samples in the composition range 0.60<x<0.70 by neutron diffraction. For all the samples Lorentzian-shaped magnetic peaks were observed at low temperatures, indicating a strong tendency toward Type III fcc antiferromagnetic order, but no evidence has been seen of a phase transition to the long-range order suggested by other experiments. The temperature dependence of the intensity and the profiles of the magnetic maxima have been measured. Some measurements of inelastic scattering in Cd _0.35Mn_0.65Te have also been carried out, revealing broad magnon-like maxima in the scattered spectra. Computer calculations of the elastic neutron scattering cross section and some other quantities characterizing the system have been performed using the Monte Carlo modelling method, and the accepted data for exchange interactions in Cd _1-xMn_xTe. The results of these calculations are discussed in the light of the experimental results.