Raman investigation of Pb-substituted Bi2Sr2Cu6+δ single crystals
| Autor: | X. Meng-Burany, X. K. Chen, A.E. Curzon, K.C. Hewitt, J. C. Irwin |
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| Rok vydání: | 1995 |
| Předmět: |
Materials science
Doping Analytical chemistry Energy Engineering and Power Technology Crystal structure Condensed Matter Physics Spectral line Electronic Optical and Magnetic Materials symbols.namesake Electron diffraction Modulation Molecular vibration symbols Electrical and Electronic Engineering Raman spectroscopy Raman scattering |
| Zdroj: | Physica C: Superconductivity. 251:192-204 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(95)00400-9 |
| Popis: | Raman scattering experiments have been carried out to investigate the vibrational spectrum of Pb-doped Bi 2 Sr 2 CuO 6+δ single crystals with molar Pb concentrations x in the range 0 ⩽ x ⩽ 0.4. The intensities and frequencies of several of the vibrational modes, with frequencies ω in the range 15 ⩽ ω ⩽ 650 cm − , are found to depend sensitively on the degree of Pb substitution. This information has been used to clarify, and in some cases confirm, the vibrational origin of the modes. The introduction of Pb into the single crystals also reduces the structural modulation that is present in the undoped crystals. The degree of modulation was monitored using electron diffraction techniques and it was found that the modulation vanished at a Pb doping level of x ≈ 0.35. The influence of the modulation on the Raman spectra was investigated and it was found that two-modes at 30 and 52 cm −1 , which were previously associated with the structural modulation, soften with Pb doping but are still present in spectra obtained from unmodulated samples. It is suggested that these modes arises from rigid layer vibrations, similar to those observed in layered dichalcagonides. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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