Energy-dispersive x-ray diffraction has been used to study the mean atomic-position distributions of V and Si atoms in a single crystal of ${\mathrm{V}}_3$Si at temperatures of 60, 180, and 300 K. The measurements included Bragg reflections with momentum transfers Q up to nearly 30 A${̊}^{\mathrm{-}1}$. Contrary to the conclusions of Staudenmann and Testardi [Phys. Rev. Lett. 43, 40 (1979)], evidence for localization of V atoms at off-lattice sites at 60 K is judged to be inconclusive. While the width of the V distribution has an anharmonic temperature dependence, the deviation from a Gaussian distribution at low temperature is found to be considerably smaller than previously reported. The Si distribution is found to become increasingly non-Gaussian at higher temperatures.

• Received 20 August 1986

DOI:https://doi.org/10.1103/PhysRevB.35.4193