Pressure-induced phase transition of CdSe and ZnO nanocrystals

After considering the effects of surface energy and surface-stress-induced pressure on the total Gibbs free energy of nanocrystals, the size-dependent solid transition pressures for CdSe and ZnO nanocrystals have been determined quantitatively. It is found that the transition pressure increases as the nanocrystals become smaller. The transition pressure change is dominated by surface-stress for CdSe, while surface energy dominates for ZnO. The calculated results are supported by the corresponding experimental results.