Как выбрать гостиницу для кошек
14 декабря, 2021
Сегодня каждый, кто собирается в отпуск и не знает, с кем оставить своего котика или кошку, может во[...]
Low temperature regime: mobile SIAs, immobile vacancies (Stage I
Between recovery Stage I and Stage III, the SIA point defects and small SIA clusters have sufficient mobility to migrate and form visible dislocation loops as well as recombine with sessile monovacancies and vacancy clusters. The defect accumulation in this temperature regime is initially linear with dose when the defect concentration is too low for
uncorrelated recombination to be a significant contribution, but then transitions to a square root dependence at an intermediate dose in pure materials when interaction between defects from different PKA
events becomes important.6,70-72,90 The critical dose
for this kinetic transition is dependent on the concentration of other defect sinks in the lattice (dislocations, grain boundaries, precipitates, etc.). The high sink strength associated with the immobile vacancies limits the growth rate (i. e., size) of the SIA loops for doses above ^0.1 dpa, and the observable defect cluster size and density typically approach a constant value at higher doses. Figure 8 shows an example of the microstructure of AlN following ion irradiation at 80 K (mobile SIAs, immobile vacancies) to a damage level of about 5 dpa.91 The microstructure consists of small (<5 nm diameter) interstitial dislocation loops.
Between recovery Stage I and Stage III, the SIA point defects and small SIA clusters have sufficient mobility to migrate and form visible dislocation loops as well as recombine with sessile monovacancies and vacancy clusters. The defect accumulation in this temperature regime is initially linear with dose when the defect concentration is too low for
uncorrelated recombination to be a significant contribution, but then transitions to a square root dependence at an intermediate dose in pure materials when interaction between defects from different PKA
events becomes important.6,70-72,90 The critical dose
for this kinetic transition is dependent on the concentration of other defect sinks in the lattice (dislocations, grain boundaries, precipitates, etc.). The high sink strength associated with the immobile vacancies limits the growth rate (i. e., size) of the SIA loops for doses above ^0.1 dpa, and the observable defect cluster size and density typically approach a constant value at higher doses. Figure 8 shows an example of the microstructure of AlN following ion irradiation at 80 K (mobile SIAs, immobile vacancies) to a damage level of about 5 dpa.91 The microstructure consists of small (<5 nm diameter) interstitial dislocation loops.