Fig. 5: Strain wave model with phase transition.
The spatial dependence of the elastic strain at different times (tagged top of each panel), for β-phase crystalites (in blue, initial fraction Xβ = 75%) remaining in the initial phase (56%, left side on each panel) and transitioning to λ (19%, right side on each panel), λ-phase crystallites (in orange) remaining in the initial phase (initial fraction Xλ = 25%, left side on each panel) and newly formed from β (19% with transformation rate rs = 0.26, right side on each panel). To distinguish the strained-transitioning crystalites from those strained-non transitioning, the former situation is contoured on each panel with a red dashed line and red arrow points to the transition direction. The solid vertical line at z = 100 nm on all panels delimits the phase-transition zone. Semi-infinite 1D medium approximates the real sample and the experimental conditions. a Initial photo-induced stress following the laser absorption profile (in red). X-ray probe depth is indicated in gray (details given in Fig. S9). The inset shows the most important values in the experiment. b–d Strain profile η(z,t) as calculated according to the model described in the main text. For transitioning crystallites (contoured dashed red) the strain due to the transition is calculated separately for the λ- and β-phase.
