W. Wasserbach et al., Low-temperature thermal conductivity of high-purity and doped tantalum single crystals after plastic deformation, PHYS ST S-B, 222(2), 2000, pp. 425-444
The thermal conductivity of plastically deformed, high-purity and doped tan
talum single crystals was measured in the temperature range between 50 mK a
nd about 2 K. The deformation was performed in such a way that comparable d
islocation arrangements and dislocation densities are produced for both, hi
gh-purity and doped specimens. Surprisingly, the thermal resistivity W-d du
e to plastic deformation depends strongly on the purity of the crystals and
the deformation temperature. In the high-purity specimens a thermal resist
ivity is observed which is much larger than in the case of doped specimens.
This additional thermal resistivity is larger after deformation at inter m
ediate temperature than after deformation at low temperatures and has to be
attributed to a dynamic interaction between phonons and non-screw dislocat
ions. In the present paper the scattering mechanism is related to oscillati
ons of geometrical kinks in non-screw dislocations.