Size Dependence of the Pressure-Induced Phase Transition in Nanocrystals

Extending the recently developed bond-order−length-strength (BOLS) correlation mechanism [Sun, C. Q. Prog. Solid -State Chem. 2007, 35, 1−159] to the pressure domain has led to atomistic insight into the phase stability of nanostructures under the varied stimuli of pressure and solid size. It turns out that the competition between the pressure-induced overheating ( T C elevation) and the size-induced undercooling ( T C depression) dominates the measured size trends of the pressure-induced phase transition. Reproduction of the measured size and pressure dependence of the phase stability for CdSe, Fe 2 O 3, and SnO 2 nanocrystals evidence the validity of the solution derived from the perspective of atomic cohesive energy and its response to the external stimulus.