On the Escaig obstacle hypothesis for cross-slip in face-centered-cubic materials

There is a significant body of literature wherein a linear approximation of Escaig's model is used to justify the large experimentally measured activation-volumes for cross-slip in face-centered-cubic copper. Here, by examining the error between the linear approximation and the original theory, we show that this explanation is not satisfactory. The calculated value for activation volume in copper, using Escaig's original equations, yields ∼60b 3 (b = Burgers vector) while the linear approximation yields 200b 3, the latter result fortuitously matching the experimental values.