Integrated X-ray intensity measurements from a solid solution of copper–gold
1955; Wiley; Volume: 8; Issue: 2 Linguagem: Inglês
10.1107/s0365110x55000406
ISSN1600-8642
Autores Tópico(s)X-ray Spectroscopy and Fluorescence Analysis
ResumoIn a solid solution random displacements of the solute and solvent ions from the mean crystal lattice are produced by the elastic strkins associated with their different sizes. A prediction of the effects on the X-ray spectrum is based on a model which treats the solute ions as centres of dilation in a finite isotropic elastic continuum. The resultant theory shows that the addition of solute atoms produces a mean lattice parameter change upon which are superimposed random displacements of the ions. These displacements result in a decrease in the integrated X-ray intensities of the high-order diffraction lines of the form associated with thermal vibrations. The effect is particularly marked in the copper-gold solid solution and comparison of the measured X-ray intensities from copper and a 15 atomic % solution of gold in copper enable one to deduce a value for the root mean square displacement ~/(~) due to distortion, when that due to thermal vibration has been allowed for. Measurements of the X-ray spectra were made using a Geiger-counter spectrometer from which it is deduced that ~/(~2) = 0.11 ~. This value compares favourably with the value predicted from the elasticity theory, namely V(~ ~) = 0.13 A.
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