A study is made of the influence of structural defects on the thermal condu
ctivity in parahydrogen crystals and in parahydrogen-orthodeuterium solutio
ns. The defects in the crystals are generated by means of a thermal shock.
The temperature dependence of the thermal conductivity is analyzed in the f
ramework of the Callaway relaxation model in the Debye approximation for th
e phonon spectrum with allowance for phonon-phonon scattering processes and
Rayleigh scattering on isotopic defects and structural defects such as dis
locations and low-angle boundaries. The effect produced in the sample by th
e thermal shock is found to depend on the deuterium concentration. In pure
parahydrogen an increase in the dislocation density is observed, and in par
ahydrogen-orthodeuterium solutions an increase in the density of low-angle
boundaries. The change in the density of low-angle boundaries in the soluti
ons after the thermal shock depends linearly on the concentration of o-D-2.
(C) 2001 American Institute of Physics.