Bi_(1.6)Pb_(0.4)Sr_(2-x)M_xCa_2Cu_3O_y(M=Mg,Ba)氧化物超导体  

OXIDE SUPERCONDUCTOR Bi_(1.6)Pb_(0.4)Sr_(2-x)M_xCa_2Cu_3O_y (M = Mg, Ba)

作　　者：卢亚锋[1] 吴晓祖[1] 李青云[1] 周廉[1] 辛绵荣[2] 罗长勋 

机构地区：[1]西北有色金属研究院,宝鸡721014 [2]陕西师范大学物理系,西安710062

出　　处：《低温物理学报》1992年第2期97-102,共6页Low Temperature Physical Letters

摘　　要：采用普通固态反应法制备了名义组分为 Bi_(1.6)Pb_(0.4)Sr_(2-x)M_xCa_2Cu_3O_y(M=Mg,Ba)的超导样品,其中 x=0;0.1;0.2;0.4.测量了样品的电阻和交流磁化率与温度的关系.当 Ba 部分替换 Sr 时,x=0.2、0.4的样品在77K 以上仅表现110K 相超导转变.X 射线衍射分析表明,Mg 或者 Ba 部分替换 Sr 虽然促进了2223相形成,但却出现了少量的2201相;而 Mg和 Ba 同时部分替换 Sr 时又抑制了2201相.XRD 及 EDXA 分析表明,Ba^(2+)实际替代Sr^(2+)的几率要比 Mg^(2+)大.The superconducting samples with nominal composition Bi1.6Pb0.4Sr2-xMxCa2Cu3Oy(M = Mg, Ba)were prepared by solid state reaction method. The resistivity and a.c. susceptibility as a function of temperature were measured for the samples. It is found that the samples with x = 0.2, 0.4 only display the superconducting transition of the 110K phase above 77K when M = Ba. XRD indicates that the partial substitution of Mg or Ba for Sr promotes the formation ability of 2223 phase, but the sample contain a small amount of the 2201 phase; the 2201 phase is prevented when Mg and Ba substituted for Sr. XRD and EDXA show that the probability of actual substitution of Ba2+ for Sr2+ is larger than that of Mg+2 for Sr+2.

关 键 词：超导体 高TC 氧化物 固态反应法 

分 类 号：O511.1[理学—低温物理]