# Properties of dislocation drag from phonon wind at ambient conditions

## TL;DR

This paper investigates how phonon wind influences dislocation mobility in crystals at ambient conditions, deriving an approximate functional form for dislocation drag as a function of velocity across different slip systems.

## Contribution

It introduces a semi-isotropic approach to model dislocation drag due to phonon wind, providing a new functional form for drag dependence on velocity at room temperature.

## Key findings

- Derived an effective functional form for dislocation drag B(v).
- Analyzed drag behavior across various slip systems and dislocation characters.
- Focused on conditions between a few percent and full transverse sound speed.

## Abstract

It is well known that under plastic deformation, dislocations are not only created but also move through the crystal, and their mobility is impeded by their interaction with the crystal structure. At high stress and temperature, this `drag' is dominated by phonon wind, i.e. phonons scattering off dislocations. Employing the semi-isotropic approach discussed in detail in Ref. [arXiv:1804.01586], we discuss here the approximate functional dependence of dislocation drag $B$ on dislocation velocity in various regimes between a few percent of transverse sound speed $c_t$ and $c_t$ (where $c_t$ is the effective average transverse sound speed of the polycrystal). In doing so, we find an effective functional form for dislocation drag $B(v)$ for different slip systems and dislocation characters at fixed (room) temperature and low pressure.