Quantum peculiarities of low-temperature kinetics of boron fracture

Kinetics of boron filament fracture in the 4.2-823 K range is investigated. Thermofluctuation fracture mechanism is disclosed in the approximately 500-800 K range based on the analysis of temperature dependences of ultimate tensile stress at different rates of loading. In the 4.2-400 K range the temperature dependences of the given characteristics turned to be different - corresponding to manifestation of quantum statistics in the oscillating state of boron. ''The characteristic temperature of fracture'' THETAsub(p) approximately equal to 1300 K is evaluated according to data on fracture kinetics that coincides with boron Debae temperature. Activation energy of boron fracture: 550 kJ/mol coinciding with sublimation energy is determined according to the data in the whole temperature range with account of quantum statistics. It is concluded that low-temperature kinetics of stressed interatomic bond rupture is caused by multidimensional tunneling (or fluctuations at zero oscillations)