The motion of single self-interstitial atoms (SIA's) in stage I of irradiated platinum was observed directly by field ion microscopy. A specimen irradiated at a temperature of 10°K with 20-keV Pt+ ions was found to contain immobile SIA's in the bulk at this temperature, as determined via pulse-field evaporation experiments. Direct observation of specimens, irradiated with 20- or 30-keV Pt+ ions, during warming experiments from 10 to 70°K showed that a flux of SIA's crossed the surface of the specimens between 13 and 25°K. Application of a diffusion model to the data yielded a value of ∼ 0.06 eV for the enthalpy change of migration and a diffusion coefficient of ∼ 0.5 exp(-0.06 eV/kT) cm2 sec -1 for the SIA.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)