Temperature Diffuse Scattering of X-Rays in Cubic Powders. II. Corrections to Integrated Intensity Measurements

Abstract

In order to obtain accurate values for the integrated Bragg intensities, it is necessary to correct for the fact that temperature diffuse scattering (TDS) peaks in the same regions of reciprocal space in which Bragg peaks occur. On the basis of recent calculation of TDS in cubic powders it is possible to calculate the contribution of TDS to apparent measured Bragg intensities. Measurements were made on a counter spectrometer using crystal-monochromated CuKα radiation. The contribution of TDS to the measured Bragg intensities is demonstrated on several peaks of lead. A simple relationship is derived for the correction and compared with a graphical solution obtained by plotting TDS under the Bragg peak. The agreement between the two methods of correcting for TDS is good. The magnitude of the correction varies with the material, the wavelength of the x-rays and the region of reciprocal space studied. For a typical material such as copper using copper radiation, the correction is about 3% of the integrated intensity. For lead, again using copper radiation, it is about 15%.