TY - JOUR
T1 - Raman scattering study of site substitution in RE1+xBa2-xCu3O7-δ (RE=Pr, La)
AU - Ren, Y. T.
AU - Xue, Y. Y.
AU - Sun, Y. Y.
AU - Chu, C. W.
N1 - Funding Information:
This work is supported in part by NSF Grant No. DMR 91-22043, DARPA Grant No. MDA 972-88-G-002, the State of Texas, NASA Grant No. NAGW-977, Texas Center for Superconductivity at the University of Houston, and the T.L,L. TemPle Foundation.
PY - 1993/8/1
Y1 - 1993/8/1
N2 - Several samples of PrBa2Cu3O0.67, Pr1+xBa2-xCu3O7-δ and La1+xBa2-xCu3O7-δ have been synthesized and examined by X-ray diffraction and polarized micro-Raman scattering. The X-ray diffraction refinement results on these samples show a decrease of the Cu(2)-O(4)-Cu(1) bond length due to partial Ba-site substitution by large radius RE-ions. The Raman scattering shows an increase of the apical O(4) stretching frequency in agreement with the structure data. The increasing of the O(4) vibration frequency with the rare-earth induced bond-length changes can account for previous seemingly contradictory Raman results on PrBa2Cu3O7. An empirical relation was found between the effective force constant k for O(4) and the Cu(1)-Cu(2) spacing d: k∝d-6. The oxygen disorder induced peak at ∼ 600 cm-1 is also discussed.
AB - Several samples of PrBa2Cu3O0.67, Pr1+xBa2-xCu3O7-δ and La1+xBa2-xCu3O7-δ have been synthesized and examined by X-ray diffraction and polarized micro-Raman scattering. The X-ray diffraction refinement results on these samples show a decrease of the Cu(2)-O(4)-Cu(1) bond length due to partial Ba-site substitution by large radius RE-ions. The Raman scattering shows an increase of the apical O(4) stretching frequency in agreement with the structure data. The increasing of the O(4) vibration frequency with the rare-earth induced bond-length changes can account for previous seemingly contradictory Raman results on PrBa2Cu3O7. An empirical relation was found between the effective force constant k for O(4) and the Cu(1)-Cu(2) spacing d: k∝d-6. The oxygen disorder induced peak at ∼ 600 cm-1 is also discussed.
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U2 - 10.1016/0921-4534(93)90781-K
DO - 10.1016/0921-4534(93)90781-K
M3 - Article
AN - SCOPUS:0027641953
SN - 0921-4534
VL - 213
SP - 224
EP - 228
JO - Physica C: Superconductivity and its applications
JF - Physica C: Superconductivity and its applications
IS - 1-2
ER -