The compensation effect for the self-diffusion of C in interstitial phases, such as the carbides of IVA and VA metals, was studied. The parameters of linear plots of ln[Do] versus Q were determined. It was noted that a wide spread of the published values of Q and Do was, in this case, due to differences in the numbers of crystal-lattice defects (including structural vacancies in the C sub-lattice of the carbides) in the starting materials. It was found that Q depended upon the electronegativity, electronic specific heat and magnetic susceptibility of the metals which formed the carbides. The atomic interaction forces in the carbides varied with changes in the vacancy concentration in the C sub-lattice.

Compensation Effect in the Self-Diffusion of Carbon in High-Melting Carbides. M.A.Shumilov, G.V.Samokhvalov: Russian Metallurgy, 1999, 3, 150-4