Anomalous compressive behavior in CeO2 nanocubes under high pressure

摘要: High-pressure angle-dispersive x-ray diffraction measurements have been performed on bulk and nanocrystalline cubic CeO2 with mean sizes of 4.7 5.6 nm. It is found that the compressibility nanocrystals lower than when a threshold pressure reached. This critical to be 10 GPa for 4.7 nm 16 GPa 5.6 nm nanocubes. The particle size dependence hardening nanoparticles quite unusual. First-principles electronic calculations show increased modulus nanocrystal due strengthening surface Ce–O bonds resulting in much larger shear consequently shell surface.