Crystal size effect on the compressibility of nano-crystalline uranium dioxide

The crystal size dependence of the bulk modulus of nano-crystalline uranium dioxide is investigated by means of in situ high pressure X-ray diffraction. Samples with average particle sizes of 4, 6 and 34 nm as measured from high resolution TEM images were studied up to 27 GPa revealing that all three nano-crystalline UO2 samples show a drastic decrease of bulk modulus with decreasing particle size. The influence of choosing the right EOS to fit the compression data is also discussed. (c) 2012 Elsevier B.V. All rights reserved.