High-purity polycrystalline samples of Bi2.1Sr1.9-xLaxCuO6+d with X=0-1 have been prepared by the polymerized complex method X-ray powder diffraction and complex magnetic susceptibility mesurements have shown that the samples are of a single-bulk Bi2201 phase without any impurity such as Bi17Sr16Cu7Oy, CuO, Bi2Sr3Cu2Oy. The dependence of the superconducting transition temperature Tc(onset) with increasing La content has a parabolic-like behavior with maximum Tc(onset)=16.6 K at x=0.3. We heve investigated the effect of La substitution for Sr on Raman spectra of Bi2.1Sr1.9-xLaxCuO6+d. The apical-oxygen phonon at ∼ 630cm-1 softens by ∼ 20 cm-1 with increasing La content, when x goes from 0 to 1. This change can be interpreted in terms of the charge redistribution induced by decreasing the Cu and Bi valences with La doping.
|ジャーナル||Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy|
|出版ステータス||Published - 1997 2月|
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