Anomalous dependence of the Debye-Waller factor in X-ray scattering on the magnitude of the transferred momentum

Abstract

According to the data of precision X-ray diffraction experiments an anomalous dependence of the Debye-Waller factor on the transferred momentum has been established in the low-momentum region for vanadium silicide and crystalline silicon, which is associated with the effect of dynamic deformation of electron shells. A second-order expansion of the electron density in pseudopotential was performed using the generalized RPA approximation, which allowed us to relate the observed anomalous dependence to the parameters of electron-electron interaction – the permittivity, pseudopotential and lattice dynamics characteristics – the nuclear correlation function. Thus, it is fundamentally possible to extract crystal microcharacteristics – the pseudopotential and permittivity – from the experimentally obtained distributions of valence electron density and the Debye-Waller factor. doi 10.33184/bulletin-bsu-2026.2.3