Displacement threshold energies in the A-15 compound V3Si

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Abstract
Changes of electrical resistivity p and critical temperature Tc were measured in the A-15 compound V3Si irradiated at low temperature (T ⋍ 21 K) by electrons of energy E. An energy range (0.20 MeV < E < 0.35 MeV) is observed where the resistivity increases, whereas the critical temperature remains constant. This result can be interpreted within the framework of the linear chain model of Labbé-Friedel as the sign that the atoms Si start to be displaced at E=0.20 MeV leading to an increase in resistivity, the critical temperature being only affected when the atoms V are displaced at E=0.35 MeV. Comparison of experimental values of damage rates determined either by p or by T c with calculated theoretical cross sections of V and Si in V3Si add some support to this interpretation. Displacement threshold energies were deduced from this analysis to be equal to (25±1) eV for Si and to (25±1) eV for V. Specific Frenkel pair resistivities were estimated as PFPSi=(4.2±0.5 μΩ.cm/at.% and PFPV=(27±3) μΏ.cm/at. % and decrease of critical temperature percent of vanadium vacancies was estimated as (2.5±0.2) K/% of displaced V atoms. Moreover, electron energy dependence of the T c decrease rate reveals the production of antisite defects for energies larger than ∼0.50 MeV. This threshold electron energy for the production of antisite defects is interpreted as the minimal energy necessary to create atomic displacements along diatomic rows of the A-15 structure along which collision replacement sequences can produce disorder.