Y_2Ba_4CuMoO_y的添加和Mo替代Cu位对YBa_2Cu_3O_(7-δ)超导体性能的影响(英文)  

EFFECT OF Y_2Ba_4CuMoO_y ADDITION AND MO-SUBSTITUTION FOR CU ON THE SUPERCONDUCTIVITY OF YBa_2Cu_3O_(7-δ)

作　　者：韩佩佩[1,2] 孙爱民[1,2] 周敏[1,2] 孙丽娜[1,2] 马书懿[1,2] 

机构地区：[1]西北师范大学物理与电子工程学院,兰州730070 [2]甘肃省原子分子物理与功能材料重点实验室,兰州730070

出　　处：《低温物理学报》2013年第4期292-298,共7页Low Temperature Physical Letters

摘　　要：本文用固相反应法制备了YBa2(Cu1-xMox)3O7-δ+x mol Y2Ba4CuMoOy(x=0.00～0.08)的一系列多晶样品.利用X射线衍射法、标准四端引线法分别对样品的物相进行了表征和超导转变温度进行了系统的测量,发现随着掺杂量的增加,样品的晶体结构有从正交相向四方相转变的趋势,超导转变温度呈金属状态到半导体状态转变的趋势,并伴有两步转变过程;同时也观察到了超导转变温度降低且转变宽度增加的现象.然而,导致低Tc和宽T的可能原因是逐渐出现的非超导相Mo2411和样品的微观结构不均匀性.通过进一步的比较观察得到,样品超导转变温度出现两步转变最可能的原因不仅与非超导相Mo2411的增加有关而且与低Tc相的形成有关.Polyerystalline samples of YBa2 （Cu1-xMox）3O7＋x molY2Ba4 CuMoOy with x =0.00,0.01,0.02, 0.03,0.04,0.05, 0.06,0.07 and 0. 08 were prepared via the conventional solid-state reaetion method. The phase identification and supereonducting transition temperature were studied by means of X-ray diffraction （XRD） and re- sistivity measurements. It is found that all samples change the structure from orthorhombie to tetragonal and the normal state resistivity shows a change from metallic to semi-conducting behavior, aeeompanied by two-step transi- tion with increasing concentration x. In addition to, a decrease in transition temperature is observed along with an increase in transition width with doping x, however, led to a deerease Tc and broad supereonducting transition may be attributed to the gradual occurrence of non-supereondueting Mo2411 addition phases and effect of microscopic in- homogeneity. It is further observed that two-step transition may be mainly due not only to the inereased amount of non-supercondting Mo2411 phase But to the formation of lower Tc phase inclusions from samples.

关 键 词：YBA2CU3O7-Δ超导体 Y2Ba4CuMoOy 添加 Mo替代 

分 类 号：TM26[一般工业技术—材料科学与工程]