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Superconductivity dependent on the amount of Bi and Sr in the Bi2Sr2CuO6 compounds

類別:期刊論文

學年 / 學期:96-1

出版日期:2007-09-01 00:00:00

著者:Wu, C. H.; Chu, Y. C.; Ling, D. C.; Liu, S. H.; Pong, W. F.; Hseu, H. S.; Chen, J. M.; Lee, J. F.; Kao, H.-C. I.

單位:淡江大學化學學系; 淡江大學物理學系

出版者:Amsterdam: Elsevier BV * North-Holland

著錄名稱、卷期、頁數:Physica C: Superconductivity and its Applications 460-462 I, pp.422-423

摘要:Two series of samples with nominal compositions of Bi2+xSr2CuOy and Bi2Sr2−xCuOy (0 ⩽ x ⩽ 0.10) were prepared by a conventional solid-state reaction method. Laminar morphology is observed for all the samples under SEM. EDS analysis shows that Bi is slightly volatile, the depletion amount is about 3% in the Bi rich samples, but only about 1% loses in the Sr deficient samples. Hole concentration of the Bi2Sr2−xCuOy series increases with increasing x, showing a hole doping effect caused by the depletion of the Sr ions. In contrary, Bi2+xSr2CuOy series has a hole filling effect by introducing the extra Bi ions. These samples show metallic conducting behavior in the normal state and superconducting property at lower temperature. Tc decreases with increasing x on both series. Bi2Sr2CuOy has the highest Tc at 7.9 K with an optimal hole concentration of 0.237. Hole concentrations obtained from the O-K edge XANES spectra and the iodometric titration agree well in these samples.

關鍵字:Superconductivity;Bi2+xSr2CuOy;Bi2Sr2−xCuOy;Hole concentration;O-K edge XANES;Bi-L edge XANES

語言:en

ISSN:0921-4534

期刊性質:國外

收錄於:SCI

國別:NLD

出版型式:紙本