The Raman scattering, electron diffraction (ED), and resistivity are measured for a nominal composition of Bi1.8Pb0.2Sr2-xCuOy system. It is found that the peaks of Alg vibrational modes of the oxygen atom in a SrO layer along the c axis are broadened, the intensity is reduced, and the position of the peak shifts toward low frequency in Raman spectra as Sr content decreases. The reduction of the incommensurate modulation wave-length is observed by ED measurements with the decrease in Sr content. This suggests that the results in Raman spectra and ED are attributed to the shift of the apical oxygen in CuO6 octahedron induced by the decrease of Sr content in Bi1.8Pb0.2Sr2-xCuOy system. The resistivity measurements show that the shift of the apical oxygen not only brings about the disappearance of superconductivity, but also induces a metal-semiconductortransition.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1999|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics