A flame-heated gas-flow furnace for single-crystal X-ray diffraction

A furnace using an inert-gas stream heated by an acetylene torch has been designed to conduct high temperature X-ray diffraction experiments. The design makes use of the stability of electrically heated gas-flow devices and the high-temperature capability of flame heaters. The gas flow is coaxial with the crystal mounting fibre resulting in a thermally stable environment controlled by the composition of the heated gas stream. Temperatures from 373 up to 1573 K are maintained by computer-controlled flow regulation of the acetylene flame based on the signal from a thermocouple on which the crystal is mounted. The results of a high-temperature X-ray diffraction study of Mg_0.54Fe²⁺_0.46Fe₂O₄, spinel are given as an example of the application of this furnace.