ВЫЧИСЛЕНИЕ КУЛОНОВСКОГО ПОЛЯ В ДИПОЛЬНОЙ РЕШЁТКЕ МЕТОДОМ ЭВАЛЬДА В ДОПОЛНЕНИЕ К МОДЕЛИ VFF ДЛЯ РАСЧЁТА КОЛЕБАНИЙ ИОННОГО КРИСТАЛЛА GaP

Дмитрий КРЫШМАРЬ, Евгений ПОКАТИЛОВ Лаборатория физики многослойных структур и молекулярного магнетизма

Abstract

In the given work dispersions of bulk crystal GaP have been calculated with the purpose of the further application of methods in practice to calculate oscillatory spectra of various nanodimensional ionic compounds from gallium phosphide and other polar materials. For resolution of convergence problem of summation of Coulomb interactions Ewald’s method has been used. In the article are presented parameters of interatomic interactions, obtained by minimization of divergence of theoretical results and experimental data. As a result it has been established twelve-parameter valence force field, where potential energy of deformation consisted of six kinds of covalent interactions (model VFF). Phonon dispersions along the main symmetry lines of the investigated crystal structure have also been calculated (directions Γ → X , Γ → K , and Γ → L in Brillouin zone). Application of model VFF and Ewald’s method has allowed with high accuracy to reproduce experimental dispersive dependences and to find a set of parameters of interatomic interactions, which can be used further for definition of energy spectrum of various nanodimensional structures from the chosen ionic material (heterolayers, heterowires, etc.).