Anisotropic Migration of Defects under Strain Effect in BCC Iron

The basic properties of defects （self-interstitial and vacancy） in/3CC iron under uniaxial tensile strain are investi- gated with atomic simulation methods. The formation and migration energies of them show different dependences on the directions of uniaxial tensile strain in two different computation boxes. In box-1, the uniaxial tensile strain a/ong the （1005 direction influences the formation and migration energies of the （1105 dumbbell but slightly affects the migration energy of a single vacancy. In box-2, the uniaxial tensile strain along the 〈111〉 direction influences the formation and migration energies of both vacancy and interstitials. Especially, a 〈110〉 dumbbell has a lower migration energy when its migration direction is the same or close to the strain direction, while along these directions, a vacancy has a higher migration energy. Aft these results indicate that the uniaxial tensile strain can result in the anisotropic formation and migration energies of simple defects in materials.