Crystallite-Conjugation Regions and Adjacent Lattice Regions in Polycrystalline Iridium: III. Enthalpies of Formation of Vacancies and the Energies of Interaction of Partners in Vacancy Complexes with Oxygen Formed in the Cores of Crystallite-Conjuga

摘要

The interatomic spacings in the cores of crystallite-conjugation regions (CCRs) and adjacent lattice regions (ALRs) of polycrystals either decrease or increase upon alloying of nominally pure metals with oxygen and vacancy complexes with oxygen (mVacO, where m is the number of vacancies in the complex) that are formed during annealing. These changes in the interatomic spacings lead to an increase or decrease in the iso-mer shifts delta of the components of the Mossbauer spectra of atomic probes ~(57)Fe that are localized in the CCR cores and ALRs of polycrystals [1-6]. The enthalpies Q_(mcmpl1 of formation of vacancy-oxygen complexes mVacO in the CCR cores have been measured for Ir and Cr polycrystals, and the enthalpies Q_(Vac),l of formation of vacancies in CCR cores have been determined for Ta, W, Ir, and Cr polycrystals. The enthalpies E_(mcmpl) of the interaction between the partners of the complexes increase with increasing number m of vacancies in the complexes.