Strain field due to point defects in metals

Abstract

The Kanzaki lattice-statics method is extended to investigate the strain field due to point defects in Al and Cu metals. The dielectric screening method is used to generate host-host and host-impurity interatomic potentials. The Ashcroft-model potential and modified Hartree dielectric function are used for host and impurity atoms. Considering the interactions up to first nearest neighbors (1NN's), the force constants, atomic displacements, and relaxation energy are calculated for substitutional alloys Al(Mg,Zn,Sn) and Cu(Mg,Zn,Sn). The atomic displacements are calculated up to 20 NN's and these are found to be both positive and negative. The maximum displacement is less than 10% of the interatomic separation. The displacements and relaxation energy in general are smaller in Al alloys than in Cu alloys.