| Summary: | 碩士 === 淡江大學 === 化學學系 === 91 === In this research, single phase Bi2(Sr2-xAx)CuOy (A = La, Gd, Y, Ca, Na) compounds with 0.05 x 0.40 were prepared by a solid state reaction method. All of them have orthorhombic symmetry. Laminar structure is observed under SEM. EDS and ICP analysis show that the prepared samples contain less amount of Bi and Na than its nominal composition, indicating that Bi and Na is more volatile than the other metal ions. Bi-2201 has a metallic normal state with a Tc(onset) at 6.1 K. All of the La doped samples have superconductivity. The maximum Tc (32 K) is found in the x = 0.05 sample. In the Gd doped samples, the maximum Tc (8 K) is found in the x = 0.05 sample. For all the Y doped samples, they are not superconducting. In the Ca series, for x 0.10, one superconducting phase was observed; for x 0.15, two superconducting phases corresponding to 2201 and 2212 are found. In the Na doped serious, only one sample with x = 0.10 shows superconductivity with Tc = 6.9 K. Hole concentration obtained from the iodometric titration and O-1s absorption spectra agrees well in the Bi-2201 and the La, Y, Ca doped samples.
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