Interstitialcy diffusion in B. C. C. metals and dilute alloys

The fundamental processes whose knowledge is necessary to the understanding of interstitialcy diffusion in bcc—as compared to fee—lattices are discussed. A major difference is that there is no possible cage effect for mixed <IIO> dumbbells in bee lattices, whatever the jump mechanism (with or without rotation) may be. Besides, jumps without rotation are favoured in bee's as compared to fee's. For these two reasons, long range diffusion of solute atoms apt to form mixed interstitials, by an interstitialcy mechanism, that is at low temperature, should be greatly favoured in bcc lattices.