Diffuse scattering of electrons in the process of ordering of the solid solution of boron in palladium PdB$_{y}$ ($y\approx1/6$)

The cluster model for the transition state is applied to explain the features of diffuse scattering of electrons, which is observed in the process of ordering of boron atoms and structure vacancies in the cubic (with the B1 structure) solid solution PdB$_y$ of boron in palladium. To simulate the diffuse intensity surface in the case of the short-range substitution order, clusters in the form of tetrahedron, octahedron, cube, and fcc unit cell including 4, 6, 9, and 14 sites of nonmetallic sublattice, respectively, are used. It has been shown that the experimental shape of the diffuse scattering contours in PdB$_{0.163}$ is best described by the model in the form of a cluster combining an octahedron and a cube.