Temperature dependences of the structural and the mechanical properties of a CdMnCrTe quaternary alloy

We investigated the structural and the mechanical properties of single crystals of the diluted magnetic semiconductor (DMS) Cd1-x-yMnxCryTe (x = 0.37, 0 ≤ y ≤ 0.03) grown by using the vertical Bridgman method. High-temperature X-ray diffraction (XRD) and microhardness measurements were carried out during heating processes at temperatures from room temperature to 750 K. The lattice constants increased with increasing temperature whereas the lattice constants decreased with increasing Cr composition y. The hardness of the Cd1-x-yMnxCryTe crystal increased exponentially with decreasing temperature for T ≤ 600 K, and it remained constant for T ≥ 700 K. The Vickers hardness, HV , decreased with increasing temperature and increased with increasing Cr composition y. The activation energy for the dislocation motion was determined from the relation between temperature and hardness.