SIZE EFFECTS OF DISLOCATION STABILITY IN NANOCRYSTALS

In this paper the size effect of lattice-dislocation stability in nanocrystals (NC's) caused by a strong interaction of dislocations with interfaces is analyzed. When the nanocrystallite size l becomes less than the characteristic length LAMBDA, a substantial dislocation redistribution in the nanocrystal may occur. This length is estimated to be dozens of nanometers and depends on the character of interfaces: coherent or incoherent (slipping), on a difference of elastic moduli of NC phases, etc. Simple analytical estimations of LAMBDA on the basis of exact calculations have been obtained.