Dislocation processes during plastic deformation of Si and Ge in the range 0.50 to 0.95 of the melting temperature

Dislocation processes occurring during plastic deformation of Si and Ge for θ = 0.50 to 0.95 (θ = T/Tm is the relative temperature) have been studied both by etch pit method and TEM. A similarity of dislocation processes in Si and Ge when compared in terms of θ has been found. In low-temperature deformation (θ = 0.5 to 0.8) dislocation glide is realized and cross slip is activated. The cross slip gives rise to a multiplication of dislocations. The interaction and multiplication of dislocations are accompanied by the formation of dipoles including faulted ones, multipoles, and bundles in slip bands. A system of Lomer dislocations is the main source of long-range internal stresses in low-temperature deformation. In high-temperature deformation (θ > 0.8) gliding of dislocations combined with climb is realized. This results in decreasing the number of dipoles and Lomer dislocations. At θ > 0.8 a main mechanism of dislocation interaction is their intersection with the degeneration of a quadrupole node into two triple ones.