Density functional theory-based derivation of an interatomic pair potential for helium impurities in nickel

Helium is formed in nickel as a by-product of neutron irradiation. Although helium is chemically inert and essentially insoluble in metals, under specific conditions it is known to cause metal embrittlement. Early experimental and theoretical studies on helium diffusion mechanisms have been a source of controversy. Recent density functional theory (DFT) studies of helium impurities in nickel contradict earlier theoretical studies. In this …