Interaction of dislocations with localized pinning points in high-purity molybdenum single crystals

The dynamic characteristics of overcoming localized pinning points by dislocations are investigated using thermal and amplitude absorption spectra of ultrasound in undeformed single crystals of T–Mo (R300/R4.2 ≈ 2 × 105); S–Mo (R300/R4.2 ≈ 6 × 103), and Ch–Mo (R300/R4.2 ≈ 3 × 103) of the orientation <110>at 88 kHz in the temperature interval of 6.5 to 300 K. Basic parameters of interaction between dislocations and pinning points are established: binding energy H0 ≈ 0.6 eV, activation volume, varying from 1.48 × 104b3 to 17b3 with the deformation amplitude from ≈ 10−6 to ≈ 10−4. The power law of interaction and the distribution function for the lengths of dislocation segments are derived. The experimental law doesn't agree with any of the known theoretical ones. In the region of low temperatures the energy dispersion of longitudinal ultrasound waves by the conduction electrons in T–Mo is proved.