A High Temperature X-Ray Diffraction Apparatus

Abstract

An apparatus is described for heating an x‐ray specimen to 1200°C in vacuum while its diffraction pattern is being recorded continuously on a Geiger counter spectrometer. The heater consists of a length of 0.030‐inch tungsten wire embedded in beryllium oxide, the whole enclosed in a polished tantalum case. Either a flat metal sheet, or powder packed in platinum gauze mounted on sheet metal is suitable as a specimen. An area about one centimeter square in the center of the specimen is irradiated by the x‐ray beam in the focusing type of spectrometer. The temperature is uniform over this area to ±5 degrees centigrade. Two concentric radiation shields reduce heat loss. The outer shield also acts as the vacuum‐tight body of the oven and has beryllium windows to pass the x‐rays. Results indicate that rapid structure changes may be observed as they occur with this apparatus.