X-ray diffraction study of TiB2, W2B4, and CrB2 at high temperatures

Abstract

This study investigates thermal expansion and thermal vibration behavior of borides using HT-XRD. In the previous research, it has been known that the vibrational behavior directly expresses the behavior of materials at high temperatures. In this work, the high temperature X-ray diffraction (HT-XRD) measurements of TiB2, W2B4, and CrB2 were conducted at the high temperature ranges; up to 1500 K. From the generated results, the study calculates thermal expansion coefficients, which coincides the previous research. Rather, the study calculates the mean square displacements of borides for evaluating the thermal vibration behaviors at elevated temperatures, demonstrating that: (1) the application of a formula into HT-XRD data could determine Debye-Waller factors of these borides; (2) a term of “agglomeration” could contribute to defining the mean square displacement u2; (3) both the Debye-Waller factor and the thermal expansion may function to design new boride-based materials at the high temperature; and (4) CrB2 has a quick increase in mean square displacement and is remarkably large value at elevated temperatures.