CVT growth, thermodynamic and magneto-structural study of Cd1-xMnxTe single crystals

The growth of Cd1-xMnxTe (with 0.5 <= x <= 0.66) single crystals by the chemical vapour transport technique in a closed tube using iodine as transport agent is reported. As regards the growth process, a qualitative thermodynamic picture of the CdTe-MnTe-I2 system is given with the aim of avoiding the presence of liquid or solid spurious species (i.e., MnI2 liquid, CdI2 liquid and MnTe2 solid. The grown single crystals showed the cubic zincblende structure; the hexagonal symmetry, verified in various cases, was found to be apparent and due to a particular type of twinning consisting in a syntaxic coalescence of cubic domains. The magnetic characterization by susceptibility measurements is reported. XPS and Auger electron spectroscopy are used for studying the electronic structure of the crystals, and for monitoring possible modifications in the chemical composition of their surface.