Diaelastic effect of self-interstitials in Fe

Abstract

Ultrasound is used to study the production and annealing of the diaelastic effect in Fe. Frenkel pairs created by 2.3-MeV-electron bombardment cause the shear moduli, C’ and ${\mathit{C}}_{44}$, to soften by (-27±2)% and (-17±4)%, per at. % pair, if resistivity per at. % pair is 20 μΩ cm. Smaller diaelastic effects were expected theoretically, given the high migration energy of self-interstitials in Fe. The magnitudes are of the same order as for Cu, but the observed anisotropy matches that detected in Mo, the only other bcc metal tested.