PHASE-TRANSFORMATIONS OF AMORPHOUS GASB-GE ALLOY AT HIGH-PRESSURES

Phase transformations occuring in the initially amorphous bulk (GaSb)( 38)Ge-24 semiconductor at pressures to 7.7 GPa and temperatures to 330 degrees C were studied using the measurement of the electrical resist ance supplemented by the X-ray examination of the samples quenched to 100 K after a high pressure treatment. The obtained experimental data and model calculations were then used to construct the T-P diagram of metastable equilibria between the crystalline metallic high-pressure p hase (hpp) and two unordered phases, semiconducting (sup) and metallic (mup), which are either amorphous or liquid depending on the temperat ure. The line of the hpp reversible arrow mup equilibrium (the malting curve of the high-pressure phase) was shown to terminate ar a critica l point where the mup becomes thermodynamically unstable as a phase. T he line of the hpp reversible arrow sup equilibrium conditions the eff ect of solid state amorphization of the high-pressure phase at decreas ing pressure.