Atomic diffusion by the dumb-bell mechanism in a concentrated random bcc alloy

Matter transport by (110) dumb-bell interstitials in the bcc random alloy i s considered in an analytical treatment based on linear response theory. Fo ur different jump mechanisms of the dumb-bell are dealt with. It was found that at a low level of approximation relations can be deduced which give tw o of the three phenomenological coefficients in terms of the third one. (Th ese relations are analogous to exact ones deduced for vacancy diffusion in the random alloy by Moleko, L. K., and Allnatt, A. R., 1998, Phil. Mag. A, 58, 666). Monte Carlo simulation shows that the relations are quite accurat e, suggesting that they may well be exact.