NEAR-SURFACE EFFECT IN SELF-DIFFUSION IN NBCX

A low diffusivity near‐surface porotion of the self‐diffusion profiles generated from thin films of 14C‐containing tracer materials is noted in three compositions of NbCx. Although commonly observed in diffusion reearch and explained in many ways, it is believed to be caused in the present case by a “delayed tracer effect” wherein nonideal boundary conditions are created by the particular tracer deposition methods, and the tracer atoms continue to enter the specimen thro ughout the time of the diffusion annealing. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA