Diffuse neutron scattering in Nb-Zr alloys

Abstract

The diffuse scattering of neutrons has been observed in the alloys ${\mathrm{Nb}}_{0.95}$ ${\mathrm{Zr}}_{0.05}$ and ${\mathrm{Nb}}_{0.88}$ ${\mathrm{Zr}}_{0.12}$ along the [111] direction around various reciprocal-lattice points. The intensity profiles were interpreted on the basis of the scattering cross section due to the lattice distortions caused by the substitutional impurity atoms. The observed peak near $\left(\frac{3}{4}\right)〈111〉$ can be related to the longitudinal phonon dispersion curve which has a local minimum near this wave vector.