A method to obtain good high-temperature X-ray patterns with a Guinier-Lenné camera

Good high-temperature X-ray patterns of metals or alloys can be obtained by reconstructing the camera support and positioning the camera in such a way that the plane of the sample is horizontal and above the X-ray source. By choosing properly oriented mica sheets as a sample support, very sharp X-ray powder patterns up to 1000°C can be obtained, which are practically free from parasitic lines due to the sample holder. This method does not require that the powder be glued to the support by refractory ceramics to prevent it from falling off at high temperatures. As an example, two phase transitions of the hydrogenated subcarbide Nb₂CH_0.3 between 20 and 1000°C are demonstrated.