缺Sr的Bi-2201相材料的微结构研究  

MICROSTRUCTURE OF Sr-DEFICIT Bi-2201 PHASE MATERIALS

作　　者：许存义[1] 毛志强[1] 左健[1] 喻伟杰 朱警生[1] 张裕恒 

机构地区：[1]中国科学技术大学结构分析开放研究实验室,合肥230026

出　　处：《物理学报》1995年第4期640-645,共6页Acta Physica Sinica

摘　　要：对名义组份为Bi_2Sr_(2-x)□_xCuO_y(x=0.1,0.2,0.3,0.4,0.5,0.6,0.7,其中□为空位)的系列样品的微结构进行了研究。电子衍射的研究表明,缺Sr的Bi-2201相的调制波长随着x值的增加而明显减小。Raman散射结果则显示随着调制波长缩短,晶体的结构畸变加剧,晶格无序度增加。利用调制的晶格失配模型讨论了这种由缺Sr所造成的结构畸变行为,并由此指出在Bi系氧化物中非公度调制与晶格的有序度很可能是相关的,调制波长缩短,晶格无序度增加;反之则减小。The microstructure of Bi2Sr2-x□xCuOy(x=0.1,0.2, 0.3, 0.4, 0.5, 0.6, 0.7, the symbol □ denotes the vacancy) was investigated. Flectron diffraction analysis shows that the wavelength of superstructural modulation in the Sr-deficit 2201 system decreases significantly with increase of x. And the Raman scattering analysis shows that the crystal structure distortion of 2201 phase intensifies with decrease in the modulation wavelength, and the degree of crystal disorder enhances correspondingly. We discuss such a structural distortion by means of the crystal misfit model, thus indicating that in bismuth cuprates the degree of crystal order is related to the characteristics of incommensurate modulation, when the modulation wavelength reduces, the degree of crystal disorder increases.

关 键 词：超导体 铋系超导体 电子衍射 微结构 

分 类 号：TM261[一般工业技术—材料科学与工程]