ATOMIC AND MOLECULAR-EMISSION ACCOMPANYING FRACTURE OF SINGLE-CRYSTAL GE - A DISLOCATION-DRIVEN PROCESS

We present evidence for the emission of atomic Ge and Ge2 molecules accompanying dynamic fracture at room temperature of single-crystal Ge under flexure loading. The emission follows the completion of crack propagation by several milliseconds and occurs in bursts, typically 1-2 ms in duration. A dislocation-driven mechanism for this emission is presented suggesting that considerable dislocation activity is accompanying failure of these samples.