Unstable interstitial-vacancy pairs and paradoxes of high temperature properties of metals

• Published in: Materials research innovations 1999-08, Vol.3 (2), p.92-96
• Main Author: Koshkin, Vladimir M.
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Exact sciences and technology; Heat capacities of solids; Heat diffusion properties; Metals; Metals. Metallurgy; Physics; Point defects (vacancies, interstitials, color centers, etc.) and defect clusters; Structure of solids and liquids; crystallography; Thermal expansion; thermomechanical effects and density; Thermal properties of condensed matter; Thermal properties of crystalline solids; Unstable defects
• ISSN: 1432-8917; 1433-075X
• DOI: 10.1007/s100190050131

There are some quite general and quite unexpected features of the high temperature behaviour of metals being reviewed by Ya. Kraftmakher. These are the discrepancy between the estimated number of point defects, determined by equilibrium and quenching experiments, the discrepancy between a number of point defects, estimated by high temperature dilatometric measurements and heat capacity ones, as well as the peculiarities in changing the self-diffusivity mechanisms at high temperatures. The mechanisms of these phenomena had been analysed, but some new qualitative and semiquantitative approaches are here suggested for explaining the named paradoxes as the basis of a model of unstable pairs vacancy-atom at interstice, being the third type of equilibrium point defects in solids, in addition to Frenkel's and Shottky's defects.