Bi系高T_c超导材料的核四极共振（NQR）研究  

NUCLEAR QUADRUPOLE RESONAANCE(NQR) STUDY IN Bi SYSTEM HIGH-Tc MATERIALS

作　　者：李建奇[1] 许亮[1] 边明华[1] 邬学文[1] 胡永祥[1] 傅耀先[1] 

机构地区：[1]华东师范大学分析测试中心,中国科学院上海冶金所

出　　处：《低温物理学报》1995年第2期147-153,共7页Low Temperature Physical Letters

基　　金：国家超导技术研究开发中心;国家教委博士点基金

摘　　要：用标准固相反应法，我们制备了Ｂｉ１．６Ｐｂ０．４Ｓｒ２Ｃａ２Ｃｕ３Ｏｙ和Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏｙ纯相样品．在液氮温度下测量了ＣＵ－ＮＱＲ和ＢＢｉ－ＮＱＲ静态谱．发现ＮＱＲ谱都为大宽包．Ｃｕ－ＮＱＲ谱线位置反映铜原子所处的氧环境．Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏｙ的ＮＱＲ谱宽反映其调制结构，Ｂｉ１．６Ｐｂ０．４．Ｓｒ２Ｃａ２Ｃｕ３ＯｙＮＱＲ谱宽取决于其掺杂浓度．由于电场梯度（ＥＦＧ）弥散很大，Ｂｉ－ＮＱＲ谱很难观察．Abstract We prepared the single phase samples of Bi1.6,Pb04, Sr2 ,Ca2Cu3Oy and Bi2Sr2CaCu2Oy with standard solid state reaction technique. We measured the NQR spectra of Bi1.6 Ph0.4Sr2Ca2Cu3Oy and Bi2Sr2CaCu2Oy at liquid nitrogen. The Cu-NQR frequency depends largely on the different oxygen coordication. The other remarkable feature of the NQR spectras of Bi system high-Tc materialas is its anomalous broadening of the spectra compared to those in the La and Y sysytem. for the Bi2Sr2CaCu2Oy, the brodened singales are attributed to the modulation of atomic due to excess oxygen ions in the Bi-O layers. for Bi1.6Pb0.4Sr2Ca2Cu3Oy. which Ph substituted into Bi2O2 bilayer substantially reduce the stuctural modulation,the most Cu-NQR linewidths are due to inhomogeneous EFG'S as a result of Ph doped.

关 键 词：BI系 高T 超导材料 NQR谱 

分 类 号：TM262[一般工业技术—材料科学与工程]