Determination of threshold energies for displacements of Fe and Rh atoms in Fe-50 at.%Rh intermetallic compound by using energetic electron irradiation at low temperatures

摘要

Changes in electrical resistivity induced by irradiation with energetic electrons were measured for Fe-50 at.%Rh alloy as a function of electron energy in the range from 0.5 to 2.0 MeV. The irradiation was carried out below 20 K and the resistivity was measured at 10 K. The electron energy dependence of the resistivity change rate was analysed by using a simple displacement theory, and the average threshold energies for atomic displacements, E_d, were determined as 30 eV for Fe and 45 eV for Rh. The analysis also revealed that resistivity values for Frenkel pairs, ρ_F (in units of μΩ cm per at.%) were 128 and 181 for Fe atom and Rh atom, respectively. The experimentally determined values of E_d and ρ_F can be used for the quantitative estimate of defect concentration in Fe-50 at.%Rh irradiated with energetic particles.