Temperature Correction for Ceramic Powder X-Ray Diffraction at a Higher Temperature

Abstract

For powder XRD measurement at a higher temperature, there is a great difference (ΔT) between the temperature (T) detected by a thermocouple in a specimen stage and the actual temperature (Ta) of the ceramic powder surface irradiated by X-ray. The BaTiO3 ceramic powder was employed to make an temperature correction on heating in light of the change of the ~ 45º characteristic peak in the vicinity of its tetragonal-cubic phase transition point (TC = 130 °C). The thermal relaxation of BaTiO3 is considered. When the BaTiO3 ceramic powder was measured at TC, the phase transition occurred at T = 170 °C and ΔT was determined as 40 °C, which is 10 °C higher than that of the ceramic bulk. The error of temperature correction is less than ± 3 °C at TC. The approximation of a linear dependency Ta - T was given as a temperature correction line between 25 and 130 °C (Ta here).