Electric features of dislocations and electric force between dislocations

Abstract

Dislocations and dislocation dynamics are the cores of material plasticity. In this work, the electric features of dislocations were investigated theoretically. An intrinsic electric field around a single dislocation was revealed. In addition to the well-known Peach–Koehler force, it was established that an important intrinsic electric force exists between dislocations, which is uncovered here for the first time and has been neglected since the discovery of dislocations. The electric forces may be large and sometimes could exceed the Peach–Koehler force for metals and some dielectric materials with large dielectric constant. Therefore, the electric force is anticipated to play a vital role in dislocation dynamics and material plasticity. Moreover, an external electric field could exert an electric force on dislocations and a threshold electric field was subsequently discovered above which this force enables dislocations to glide. Interestingly, it was found that some dislocations move in one direction, but others move in reverse in an identical electric field, which is in agreement with experimental observations. Despite dislocation motion under an electric field, to one’s surprise, both edge and screw dislocations do not carry net charges by themselves, which may tackle the long-standing puzzle on the charges of dislocations. These findings may supply people with new fundamental knowledge on dislocations as well as dislocation dynamics, and may assist people in understanding related phenomena.

Well-designed internal electric field from nano-ferroelectrics promotes formic acid oxidation on Pd

“…Moreover, the glide of Pd atoms could also occur during the reduction of PdCl 4 2− ions by H 2 with the presence of the electric field from TNPs. 41 Therefore, the shift of Pd diffraction peaks basically shows that the crystal structure of the Pd NPs shrinks (listed in Table S3†), which may be due to the dislocations induced by the polarized electric field of tourmaline. 41,42…”

“…41 Therefore, the shift of Pd diffraction peaks basically shows that the crystal structure of the Pd NPs shrinks (listed in Table S3†), which may be due to the dislocations induced by the polarized electric field of tourmaline. 41,42…”

“…During the synthesizing procedure, PdCl ions by H 2 with the presence of the electric field from TNPs. 41 Therefore, the shift of Pd diffraction peaks basically shows that the crystal structure of the Pd NPs shrinks (listed in Table S3 †), which may be due to the dislocations induced by the polarized electric field of tourmaline. 41,42 To obtain an insight into the structure of the as-synthesized Pd-based catalysts, the morphology and particle size of the assynthesized catalysts were determined by SEM and TEM images.…”