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High‐pressure Raman study on CeO 2 nanospheres self‐assembled by 5 nm CeO 2 nanoparticles
Author(s) -
Liu Bo,
Liu Bingbing,
Li Quanjun,
Li Zepeng,
Yao Mingguang,
Liu Ran,
Zou Xu,
Lv Hang,
Wu Wei,
Cui Wen,
Liu Zhaodong,
Li Dongmei,
Zou Bo,
Cui Tian,
Zou Guangtian
Publication year - 2011
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201000807
Subject(s) - raman spectroscopy , materials science , fluorite , nanoparticle , nanomaterials , hydrostatic pressure , phase (matter) , nanotechnology , particle size , phase transition , chemical engineering , chemistry , optics , condensed matter physics , metallurgy , thermodynamics , physics , organic chemistry , engineering
Abstract CeO 2 undergoes a first‐order phase transition from fluorite to α‐PbCl 2 ‐type structure under high pressure. To evaluate the changes in physical properties of CeO 2 nanomaterials as the particle size decreasing, high‐pressure Raman study under quasi‐hydrostatic condition has been performed on CeO 2 nanospheres self‐assembled by 5 nm CeO 2 nanoparticles at room temperature. Surprisingly, as the pressure elevate to 34 GPa, the CeO 2 nanospheres still retain the cubic fluorite‐type structure, indicating the sample is more stable than the bulk counterpart. Whereas, previous high‐pressure studies show the phase transition at 22.3/26.5 GPa for 12 nm CeO 2 nanoparticles, which is less stable than the bulk materials. The enhancement of phase stability might be attributed to the increase of surface energy of CeO 2 nanospheres as the size of the building units decrease.