The effect of temperature on local order diffuse scattering from alloys

<h2>Acta Crystallographica</h2><h3></h3><h3>0365-110X</h3> <h2>research papers</h2> Volume 14 Part 11 Pages 1170-1176 November 1961 <h2>The effect of temperature on local order diffuse scattering from alloys</h2> C. B. Walker and D. T. Keating Acta Cryst. (1961). 14, 1170 The Effect of Temperature on Local Order Diffuse Scattering from Alloys. I* BY C. B. WALKER Institute for the Study of Metals, University of Chicago, Chicago 37, Illinois, U.S.A. ~D D. T. KV,~TmG Broolchaven National Laboratory, Upton, Long Island, N.Y. (Received 1 December 1960) The theory of the diffuse scattering of X-rays from binary alloys with local order has been extended to include explicitly the effects of thermal vibrations. By adopting certain simplifying assumptions about the lattice vibrations it is found that the thermal effects can be expressed in the form of appropriate Debye-Waller factors modifying the usual diffuse scattering terms. Experimental measurements verify the predicted general nature and magnitude of the temperature effect. Neglect of this effect appears to be a significant source of error in past experimental determinations of local order in alloys. Introduction Diffraction theory describing the diffuse X-ray scat- tering arising from local orderingt of the atoms in a binary alloy has been extended to include the modify- ing effects of static displacements due to differing atomic sizes by several authors [see, for example, Huang (1947); Warren, Averbach & Roberts (1951); Boric (1957), (1959)], but the analogous extension to include the effects of the dynamic displacements due to thermal vibrations has received relatively little ~tt0ntion, Muld~wor (1954) ~ttempted to develop a...