TY - JOUR
T1 - Lattice constants and electron gap energies of nano- and subnano-sized cerium oxides from the experiments and first-principles calculations
AU - Tsunekawa, S.
AU - Wang, J. T.
AU - Kawazoe, Y.
N1 - Funding Information:
We are grateful to the staff of the Center for Computational Materials Science at IMR (Tohoku University) for their continuous support of the supercomputer facilities. J.-T. Wang would like to thank the JSPS for the financial support.
PY - 2006/2/9
Y1 - 2006/2/9
N2 - Experiments reveal that the lattice constants of nanocrystallites with the number of CeO2-x formula units N more than 68 expand relative to the bulk CeO2 but are very different depending on the fabrication method. Densities of states are calculated for bulk CeO2 and CeO 1.5, and for (CeO2)13 and (CeO 1.5)13 clusters. Band gap energies of the bulk CeO 2 and CeO1.5 are estimated to be 3.20 and 0.30 eV, respectively. HOMO-LUMO gap energies of the clusters (CeO2) 13 and (CeO1.5)13 are calculated to be almost 0 and 3.05 eV, respectively. Experimental results of the ultraviolet absorption of nanocrystallites with the number of CeO2 and CeO1.5 formula units more than 68 show the blueshifts from the bulk CeO2 and CeO1.5, respectively, due to the quantum confinement effect.
AB - Experiments reveal that the lattice constants of nanocrystallites with the number of CeO2-x formula units N more than 68 expand relative to the bulk CeO2 but are very different depending on the fabrication method. Densities of states are calculated for bulk CeO2 and CeO 1.5, and for (CeO2)13 and (CeO 1.5)13 clusters. Band gap energies of the bulk CeO 2 and CeO1.5 are estimated to be 3.20 and 0.30 eV, respectively. HOMO-LUMO gap energies of the clusters (CeO2) 13 and (CeO1.5)13 are calculated to be almost 0 and 3.05 eV, respectively. Experimental results of the ultraviolet absorption of nanocrystallites with the number of CeO2 and CeO1.5 formula units more than 68 show the blueshifts from the bulk CeO2 and CeO1.5, respectively, due to the quantum confinement effect.
KW - Ab initio calculation
KW - Band gap energy
KW - Cerium oxide
KW - Cluster
KW - Core-shell structure
KW - Nanocrystallite
KW - Size effect
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U2 - 10.1016/j.jallcom.2004.12.140
DO - 10.1016/j.jallcom.2004.12.140
M3 - Conference article
AN - SCOPUS:31344453309
SN - 0925-8388
VL - 408-412
SP - 1145
EP - 1148
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
T2 - Proceedings of the Rare Earths'04 in Nara, Japan
Y2 - 7 November 2004 through 12 November 2004
ER -