STRUCTURAL STUDY AND PHASE DIAGRAM OF THE ALLOY SYSTEM Cu2Zn1-zMnzSnSe4

Abstract

The structural study and phase diagram of the alloy system Cu2Zn1-zMnzSnSe4 are reported. Polycrystalline samples were synthesized using the direct fusion and annealing technique from the constituent elements. X-ray diffraction analysis indicates that system crystallizes in the tetragonal stannite structure with a possible I42m space group. From differential thermic analysis (DTA) experiment the phase diagram was constructed for alloy system, which suggests that the region between 600 and 700 °C is biphasic coexisting stannite and wurtz-stannite phases (a+d). The peritectic decomposition of the system d ® (L+ZnSe) in the region between z = 0 and z ~ 0.80 occurs at ~ 800 ºC, for z > 0.80 the peritectic temperature decreases to ~700 ºC with z = 1.0. The transition of liquid L to (L+ZnSe) is given by the boundary line between 1075 ºC with z = 0 and ~770 ºC with z ~ 0.80. The region of the diagram below 600 ºC corresponds to the appearance of the tetragonal stannite phase, as it indicated by the X-ray diffraction study at room temperature.