The grain boundary diffusion of Te in Ag was studied over a temperature range of about 600K by using 121Te and 123Te radio-tracers. It was found that, at between 378 and 504K, a type-C Harrison regime existed; which permitted direct measurements to be made of the grain-boundary diffusion coefficient. The results were described by:

D(m2/s) = 1.01 x 10-4exp[-86.75(kJ/mol)/RT]

C.Herzig, J.Geise, J.Mishin: Acta Metallurgica et Materialia, 1993, 41[6], 1683-91