Vacuum furnace for high temperature X-ray diffractometry

A vacuum furnace, to be used in conjunction with an X-ray diffractometer, for studying phase changes and solid state reactions at high temperatures is described. The sample is heated, primarily by radiation, from a platinum/20% rhodium heating element. The present temperature range is from room temperature to 1200° C, but a slight modification to the sample holder should allow temperatures of about 1600° C to be reached. Cooling of the furnace jacket is so efficient that simple O-ring principles are used to obtain the desired vacuum conditions. The sample holder is controlled from the outside and can be removed without in any way disturbing the rest of the furnace components. Data on temperature calibration and the experimentally determined inversion temperatures of quartz and iron are given. Decomposition studies of potassium and silver permanganates and phase changes in the iron carbide system, which are now in progress, illustrate the type of investigations which can be undertaken with this instrument.