“…A calculation of the temperature of the nanocrystals after carrier thermalization, but before the onset of any phase transformation, provides the thermal-driving force for the phase transformation. Within the extinction depth of the light, the temperature increase caused in a material by an incident laser pulse may be described by the equation DT ¼ aF CN ¼ 572 C, where a (1.92 Â 10 5 cm À 1 ) is the optical cross-section, F is incident laser fluence (8 mJ cm À 2 ), C is the specific heat (76.3 J/mol K) and N is the molar density 44,10 . Note that one does not include the latent heat of the superionic transformation when calculating the driving force temperature, as the low-temperature phase has only been superheated and has not yet transformed.…”