Effect of silicon anisotropy on the stability of thermomigration of linear zones

New types of instabilities associated with crystal anisotropy during thermomigration of rectilinear and curvilinear (annular) zones under the action of a temperature gradient in the silicon-aluminium system are experimentally revealed. A force model of thermomigration is improved, which takes into account vectors of resistance forces to atomic-kinetic processes at the dissolution front. This model explains the observed features of the stable and unstable motion of the linear zones. Reasons and a mechanism of thickenings and kinks of the ends of rectilinear zones, their fragmentation and decay, as well as transformation of annular linear zones into triangular and square zones during thermomigration in the < 111 > and < 100 > directions, respectively, were also explained.