Peierlsbarriere

Peierls barrier is a theoretical concept in materials science and solid-state physics that describes a critical concentration of defects in a crystal lattice above which the recovery of defects becomes spontaneous. This phenomenon was first proposed by Rudolf Peierls in the 1940s and is also known as the Peierls stress or the Peierls force.

The Peierls barrier arises from the interplay between elastic and atomic forces within a crystal lattice. When a crystal is subjected to a mechanical stress, the lattice will deform and accommodate the stress through a process known as dislocation. However, there is a limit to the amount of stress that a crystal can withstand before the lattice is unable to deform further. This limit is known as the Peierls stress.

The Peierls barrier concept is crucial in understanding the mechanical behavior of materials, particularly under conditions of high stress and strain. A lattice subjected to high stress will attempt to relieve the stress by creating dislocations. If the stress is above a certain critical value, known as the Peierls stress, the recovery of dislocations will occur spontaneously, leading to plastic deformation of the material.

The Peierls barrier is a thermodynamic and kinetic barrier that inhibits the recovery of dislocations, and hence affects the strength of a material. A higher Peierls barrier indicates higher strength and stiffness of the material, while a lower barrier suggests lower strength and higher ductility. The Peierls barrier concept has implications for various applications, including the design of materials for use under extreme conditions of stress and temperature.