Strong, surprising, and multifaceted effects of the width of the external surface layer ${\Delta }_{\xi }$ and internal stresses on surface-induced pretransformation and phase transformations (PTs) are revealed. Using our further developed phase-field approach, we found that above some critical ${\Delta }_{\xi }^{*}$, a morphological transition from fully transformed layer to lack of surface pretransformation occurs for any transformation strain ${\mathit{\epsilon }}_t$. It corresponds to a sharp transition to the universal (independent of ${\mathit{\epsilon }}_t$), strongly increasing the master relationship of the critical thermodynamic driving force for PT $X_c$ on ${\Delta }_{\xi }$. For large ${\mathit{\epsilon }}_t$, with increasing ${\Delta }_{\xi }$, $X_c$ unexpectedly decreases, oscillates, and then becomes independent of ${\mathit{\epsilon }}_t$. Oscillations are caused by morphological transitions of fully transformed surface nanostructure. A similar approach can be developed for internal surfaces (grain boundaries) and for various types of PTs and chemical reactions.

• Received 14 June 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.175701