STRUCTURAL-PROPERTIES OF CD1-XMGXTE AND CD1-X-YMGXMNYTE CRYSTALS

Electron probe microanalysis and X-ray diffraction studies have been p erformed on samples of ternary Cd1-xMgxTe (0.05 less-than-or-equal-to z less-than-or-equal-to 0.09) and quaternary Cd1-x-yMgxMuyTe (0.025 le ss-than-or-equal-to x less-than-or-equal-to 0.4; 0.025 less-than-or-eq ual-to y less-than-or-equal-to 0.7) alloys. The investigated samples w ere cut froin 24 different ingots grown by Bridgman method. Microprobe examinations have revealed significant differences between actual and nominal content of Mg along the longitudinal direction for both terna ry and quaternary ingots. In contrast to Mg, for most Cd1-x-yMgxMnyTe samples the actual Mn content was within +/-5% of nominal content. The lattice constants have been determined by X-ray powder diffraction me thod. Whereas Cd1-x-yMgxMnyTe samples exhibit only zinc blende crystal structure for the entire region of x and y investigated, the Cd1-xMgx Te alloy has two different structures depending on Mg content; a zinc blende structure below x = 0.5 and a wurtzite structure above it. In b oth alloys the lattice constant decreases with increasing Mg content.