INVESTIGATION OF THE EFFECT OF VACANCIES ON THE PROCESS OF NICKEL IMPURITY SEGREGATION NEAR THE BOUNDARIES OF DEFECTS IN THE STRUCTURE OF IN LSNT PEROVSKITE BY THE METHOD OF AB INITIO MOLECULAR DYNAMICS

Abstract

In this paper, we investigate the segregation of Ni impurities in the presence of oxygen vacancies near the boundaries of defects in the structure of perovskite La0.2Sr0.7Ni0.1Ti0.9O2.9 (LSNT), using the example of a model cell with stoichiometry La0.5Sr0.5TiO3 (LST). Lattice defects such as TiO-terminated surface (001) and TiO-terminated antiphase boundary are considered. The VASP package is used to perform quantum mechanical calculations of energies. As a result, it was found that Ni impurity particles tend to segregate at the boundaries of defects for both the surface and the antiphase boundary. Besides, oxygen vacancies enhance the process of segregation. These results confirm experimental observations.