Abstract Herein are presented the results of an experimental study of a ternary calcogenide glass of composition: 55 at.% As, 35 at.% Te, 10 at.% Ge. X-ray diffraction measurements of powder samples of the glass were made over a temperature range from room temperature (~23° C) to 440° C. These measurements show the glass to be in a non-cyrstalline amorphous state or short-range order state from room temperature up to a temperature of 220° C. From 220° to approximately 440° the material seems to...