Confirmation of the Grube-Jedele Procedure in Processing Interdiffusion Data in Binary Alloys

The 1932/1933 experiments of Grube-Jedele (G-J) reveal their discovery that 0–100 at. pct diffusion penetration curves can generate monotone composition-variant interdiffusion coefficients, \( \tilde{D}\left( X \right) \). G-J templated a smoothed infinite couple sectionally and sequentially curve via a set of constant \( \tilde{D} \) error function curves with local 2- and 3-point determined. The first and second derivatives created a monotone sequence of coefficient values. We detail this in processing G-J curves, remarkably revealing as with constant \( \tilde{D} \), that variable \( \tilde{D} \) obtained generates a \(\root{}\of{(t)}\) penetration dependence. This finding was later verified analytically via Ginzburg-Landau’s (G-L) 1950 variational-quantum, lattice-dynamical requirement that \( \tilde{D} \) lies outside the Fickian second derivative. The G-L and G-J procedures and analyses were supported in 1947 by Smigelskas and Kirkendall’s experimental discounting of Boltzmann’s 1897 purely mathematical theorem.