S.M. Klotsman

Super-High Concentrations of Vacancies in Regions of High Concentration of Point Defects and Composition of Vacancy-Oxygen Complexes in These Regions in Pd, Ta, W and Pt Polycrystals

The delivery of vacancies from the core of crystallite conjugation regions (CCRs) to the region in the crystallite volume with a high concentration of point defects (HCPD), which is adjacent to the CCRs core, limits the formation of oxygen-vacancy complexes in the HCPD region in Pd, Ta, W and Pt. The number of partners in complexes having a minimum size, which depended on the formation temperature of the complexes, was estimated. At a temperature sufficient for full compensation of relaxation volumes of point defects in the HCPDR lattice, the complexes consisted of one oxygen impurity and three vacancies. At the detection threshold temperature, the complexes included only one vacancy and two oxygen impurities. The formation activation enthalpy of the vacancies in the HCPD region accounted for about 15% of the formation activation enthalpy of equilibrium vacancies in the bulk and exhibited a linear dependence on universal homologous tempera-