Low-temperature unsteady creep of parahydrogen single crystals

Abstract

The low-temperature plasticity of single crystals of solid parahydrogen (orthohydrogen concentration ∼0.2%, nonhydrogen impurities ∼1.5×10−4%, and isotopic impurities of hydrogen — deuterium — [D]/[H]∼(5–6)×10−3%) in the is investigated in the temperature range 1.8–4.2 K under conditions of sample creep under the influence of a static mechanical stress σ. A complicated dependence of the constant of the logarithmic creep of p-H2 on the stress and temperature is observed, along with the anomalous features of the creep that indicate either the possible involvement of vacancies in the kinetics of the unsteady creep of parahydrogen single crystals at small σ or the coherent motion of kinks on dislocations.