Deformation kinetics within cylindrical micropores of glassy solid 4He at very low temperatures

Abstract

AbstractThe deformation kinetics for glassy solid helium confined in microscopic domain at very low temperature regime was investigated using a transition‐rate‐state dependent model considering the shear thinning behavior which means, once material being subjected to high shear rates, the viscosity diminishes with increasing shear rate. The preliminary results show that there might be nearly frictionless fields for rate of deformation due to the almost vanishing shear stress in micropores at very low temperature regime subjected to some surface conditions: The relatively larger roughness (compared to the macroscopic domain) inside micropores and the slip. As the pore size decreases, the surface‐to‐volume ratio increases and therefore, surface roughness will greatly affect the deformation kinetics in micropores. By using the boundary perturbation method, we obtained a class of temperature and activation energy dependent fields for the deformation kinetics at low temperature regime with the presumed small wavy roughness distributed along the walls of an cylindrical micropore. The critical deformation kinetics of the glassy matter is dependent upon the temperature, activation energy, activation volume, orientation dependent and is proportional to the (referenced) shear rate, the slip length, the amplitude and the orientation of the wavy‐roughness. Finally, we also discuss the quantitative similarity between our results with Ray and Hallock [Phys. Rev. Lett. 100, 235301 (2008)].