Direct measurement of isothermal compressibility of amorphous semiconductors

The isothermal compressibilities of the chalcogenide glasses Te₁₅Ge₃As₂, Te₁₅Ge₂As₃ and As₂Se₃ have been measured to 5 kbar by direct measurement of the change in sample length using a differential transformer placed inside the hydrostatic pressure vessel. Calibration data was obtained from the measurement of the compressibilities of alkali halide single crystals. For Te₁₅Ge₃As₂, the isothermal compressibility was found to be 6.00 × 10^?12 ? 0.7 × 10^?22P cm²/dyne; for Te₁₅Ge₂As₃, 5.58 × 10^?12 + 0.3 × 10^?22P cm²/dyne; for As₂Se₃, 6.30 × 10^?12 ? 0.8 × 10^?22P cm²/dyne where P is the pressure in dynes/cm². Errors are near 5%.