Investigation of the interatomic potential using the crystal gamma-ray-induced Doppler-broadening method on oriented Ni single crystals

摘要

The gamma-ray-induced Doppler-broadening method, relying on high-resolution gamma-ray spectroscopy, involves direct measurement of the Doppler broadening of gamma rays emitted when nuclei decay in flight following recoil induced by preceding gamma rays. This method is used to study interatomic collisions at low energy in solids and in this way to probe the repulsive interatomic potential. Line shapes of gamma rays, emitted by the recoiling Ni-59 isotope after thermal neutron capture in Ni single crystals, were measured and compared to results obtained by molecular dynamics simulations of the slowing down. Several potentials (including different embedded-atom method potentials) are investigated using the observed fine structure of the line shape, which depends on the crystal orientations. From a detailed study of the line shapes measured in two different orientations, a new potential is then derived. [S0163-1829(99)06409-7]. [References: 31]