【摘要】 自今年 3月在NaxCo2 O4 +yH2 O中发现超导电性以来 ,具有层状结构的Co系氧化物又受到人们广泛的关注 .本文在成功合成具有misfit层状结构Bi2 Sr2 Co2 Oy 单相样品的基础上 ,通过Pb对Bi的部分替代、以及I的插层 ,成功地使其c轴由 1.4 9nm增至 1.87nm ,并对其输运性质和磁性质进行了系统研究 .结果发现 :Pb的部分替代并没有使该体系的电阻 温度关系行为发生显著变化 ,但在低温下使样品呈现自旋玻璃态行为 ;I的插入不仅使其c轴长度增加 ,而且样品变为半导体 ,并不呈现超导电性 ,在低温下同样呈现自旋玻璃态行为 .同时对Pb替代及I插层效应进行了讨论更多还原

【Abstract】 Since the discovery of superconductivity in Na x Co 2O 4+ y H 2O compound in March, much attention had been focused on the cobalt compounds that contain hexangular CoO 2 layers. In this paper, the polycrystalline samples of Bi 2- x Pb x Sr 2Co 2O 8 ( x =0, 0.1, 0.2 , 0.3, 0.4, 0.5 and 0.6) were synthesized. And iodine was successfully inserted between Bi-O layers in these samples. It was found that their c axis length increased from 1.49nm to 1.87nm. The studies on their structure, transport properties and magnetic properties were systematically carried out. A spin-glass transition at about 4K was observed in all the Pb-doped samples. With the insertion of iodine between Bi-O layers, the sample turns into a semiconductor instead of a superconductor, and also shows the spin-glass behavior at low temperature. The effects of Pb partial substitution and I insertion were discussed in detail.更多还原