Dependence of electron-lattice scattering cross sections on crystallographic orientations in Al2O3 and Mg2SiO4

We use the dynamical structure factor (DSF) based cross sections to study effects of crystal anisotropy on electron-lattice coupling. Being the Fourier transform of the lattice pair correlation function, the DSF considers manifestations of anisotropy in correlations between atomic positions as well as dynamics of atoms in a crystal. We demonstrate that even a weak anisotropy of α-Al2O3 and Mg2SiO4 crystals results in a difference between momenta transferred from an electron to the lattice along different crystallographic planes. This dependence can be important when describing relaxation of intense electronic excitation caused by impact of swift heavy ions or femtosecond laser pulses.