Protodefect as a Basis of Multilevel Nanoscale Plasticity of Crystal Materials

Atomic mechanisms of plastic deformation initiation in materials with crystal structure are investigated. It is shown that thermal fluctuations can be a reason for structural defect generation and there is a threshold strain value at which zones with local structural changes (protodefects) grow almost abruptly. The calculations illustrate that protodefect formation is induced by a local expansion of atomic volume.