Experimental determination of U diffusion in α-Zr

Abstract

U bulk diffusion in α-Zr was measured by mean α-spectrometry in the temperature range 763–1123K (540–850°C). A deviation from the Arrhenius law consistent in a downward curvature was observed; such anomaly is similar to the self and hetero substitutional diffusion previously measured in α-Zr matrix.The measurements are compatible with the existences of migrating Fe–vacancy complex that could be competitive with a simplest single vacancy mechanism for substitutional diffusers. The possibility that this could be the reason for the non Arrhenius behaviour is discussed.