Microstructural changes and point defect behaviour in V, and alloys containing 0.2, 0.3 or 3.5at%Fe, were studied by using high-voltage electron microscopy. During irradiation, interstitial-type dislocation loops were formed and grew. The saturated loop number-densities in the V-Fe alloys were much higher than those in pure V; thus indicating that

Fe atoms in the matrix strongly interacted with, and trapped, self-interstitial atoms. The shapes of the loops which were formed in the V-Fe alloys were complicated. Loops which grew larger than 100nm had stacking fault-like shapes. These complicated shapes became more marked with increasing Fe concentration This implied that Fe atoms segregated to loops via a strong interaction with self-interstitial atoms. Apparent migration energies of 0.21 and 0.81eV were deduced from the temperature dependence of the loop number-density for pure V and V-Fe, respectively. The observed phenomena were explained in terms of the obtained binding energy.

Study of Point Defect Behaviours in Vanadium and its Alloys by Using HVEM. T.Hayashi, K.Fukumoto, H.Matsui: Journal of Nuclear Materials, 2000, 283-287, 234-8