TY - JOUR
T1 - XAFS study of A-site-deficient La0.63Ti0.92Nb 0.08O3 perovskite
AU - Yoshiasa, Akira
AU - Okube, Maki
AU - Okudera, Hiroki
AU - Nakatsuka, Akihiko
AU - Yashima, Masatomo
AU - Sakai, Atsushi
AU - Mori, Mizuki
AU - Ali, Roushown
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005
Y1 - 2005
N2 - The temperature dependence of EXAFS Debye-Waller factors in La 0.63Ti0.92Nb0.08O3 perovskite with cation deficiency was investigated with the cumulant expansion method. The measurements of the Ti and Nb K-edge and La L3-edge EXAFS spectra were carried out in the transmission mode at temperatures up to 800 K. The obtained local bond distances of 1.95(1) Å for Ti-O, 1.98(1) Å for Nb-O and 2.65(1) Å for La-O are significantly smaller than the expected values on Shannon's radii. This characteristic is attributable to the presence of the cation deficiency. The effective pair potentials, V(u) = αu2/2 + βu3/3, were evaluated and the potential coefficients α and β for the Ti-O bond in La0.63Ti0.92Nb 0.08O3 are 6.6(1) eV/Å2 and -42(3) eV/Å3, respectively. The Ti-O bond in the A-site-deficient La0.63Ti0.92Nb0.08O3 has relatively larger anharmonic and soft potential coefficient than that in ordinary CaTiO3 perovskites.
AB - The temperature dependence of EXAFS Debye-Waller factors in La 0.63Ti0.92Nb0.08O3 perovskite with cation deficiency was investigated with the cumulant expansion method. The measurements of the Ti and Nb K-edge and La L3-edge EXAFS spectra were carried out in the transmission mode at temperatures up to 800 K. The obtained local bond distances of 1.95(1) Å for Ti-O, 1.98(1) Å for Nb-O and 2.65(1) Å for La-O are significantly smaller than the expected values on Shannon's radii. This characteristic is attributable to the presence of the cation deficiency. The effective pair potentials, V(u) = αu2/2 + βu3/3, were evaluated and the potential coefficients α and β for the Ti-O bond in La0.63Ti0.92Nb 0.08O3 are 6.6(1) eV/Å2 and -42(3) eV/Å3, respectively. The Ti-O bond in the A-site-deficient La0.63Ti0.92Nb0.08O3 has relatively larger anharmonic and soft potential coefficient than that in ordinary CaTiO3 perovskites.
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U2 - 10.1238/Physica.Topical.115a00372
DO - 10.1238/Physica.Topical.115a00372
M3 - Conference article
AN - SCOPUS:42149162223
VL - T115
SP - 372
EP - 374
JO - Physica Scripta
JF - Physica Scripta
SN - 0031-8949
T2 - 12th X-ray Absorption Fine Structure International Conference, XAFS12
Y2 - 23 June 2003 through 27 June 2003
ER -