Plasticity at crack tips in Gd3Ga5O12 garnet single crystals deformed at temperatures below 950°C

Single crystals of Gd₃Ga₅O₁₂ have been strained under confining pressure (1 5 GPa) at temperatures below 950°C. No evidence for macroscopic plasticity was found, but transmission electron microscopy revealed dislocation generation at crack tips. Deformation mechanisms are different from those operating in the high-temperature regime: extending stacking faults in {110} planes and the 〈010〉{100} glide system were observed. Dissociations of a/4〈111〉 partial dislocations were also observed.