Theory and experiment on deviations of Matthiessen's rule in dislocated crystals: a constructive reply

Abstract

In a recent comment, Kaveh and Wiser (1986) defend their theory on deviations of Matthiessen's rule (DMRs) by questioning related experiments of the author's on aluminium, because of inconsistencies in experimental data as well as fatal influences of an extended size effect. The present reply points out essential errors with both criticisms and thus strongly insists on the validity of the experiments originally reported. The DMRS are far smaller than predicted by Kaveh and Wiser. Nevertheless, owing to some correlation of data in literature with deformation mode and annealing treatment, the DMRs appear to arise from long-range strain fields close to the dislocations. This suggests that the Kaveh-Wiser theory could apply for particularly strain-intensive dislocation arrays and help to quantify the dilatation-specific part of dislocation resistivity.

Thermopower and resistivity due to dislocations in monovalent metals

“…It is obvious that the variation of n from 0 to 0.9 results in a change of the dislocation residual resistance, from 1.95 to 1.76 × 10 −13 µ cm 3 ; this is by about 10%. The measured values of the dislocation resistivity ( ρ d /N d ) exp for copper are within the interval (1.3-2.3) × 10 −13 µ cm 3 [10]; more rigorous analysis gives (1.6±0.2)×10 −13 µ cm 3 [3]. Therefore, the calculated value of ρ d /N d agrees quite well with the measured one for any R 1 .…”

“…It can now be confidently stated that there are two basic mechanisms responsible for the scattering of conduction electrons by dislocations: the first is connected with the long-range elastic strain fields and the second with the short-range inelastic distortion of the lattice in the dislocation core [8,9]. The investigations performed during the last few years have shown that a dislocation's elastic strain field causes the smallangle scattering of electrons, whereas the dislocation core causes the large-angle scattering [10,11]. The former exhibits strong deviation from Matthiessen's rule, i.e.…”

Electrical dislocation resistivity and anisotropic scattering in high‐purity copper single crystals

“…Al =Airn arid Q , = according to Table 1, A2 = Apil = 0.84 [4, 121 and el, = eph = 194.5 nQ cm [7] at 77 K (ph is the index for electron-phonon scattering), A3 = Adis and e3 = ed are unknown but can be fixed by (4) arid (5).…”

“…As shown in [a] it seems to be important to get rid of the influence of the grain size which could falsify the anisotropy parameters of electron-impurity (Ai,n) and electron-dislocation scattering (Adis). Only then it could be expected to observe some possible influence of the long-range strain field of the dislocations [5] on DMR and LFHE.…”