X-RAY DETERMINATION OF DEBYE TEMPERATURE OF URANIUM MONOCARBIDE

Bragg reflections by single crystals of UC, cleaved along (100) planes, were found to have negligible extinction for values of sin ϑ/λ in the range from 0.4 to 1.2 Å−1. The integrated intensities of these reflections were measured by using MoKα radiation at various temperatures from 77 to 773 °K. Plots of the logarithm of the integrated intensities vs. temperature, or vs. (sin ϑ/λ)2 at a fixed temperature, were straight lines. The slopes of the plotted lines yielded an average value θM = (265 ± 5). °K for the Debye temperature defined in terms of the uranium atoms only, and θM = (366 ± 7) °K, using the average of the U and C masses in the Debye‐Waller factor. These values are compared with those determined by different experimental techniques. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim