Bi-2223/Ag超导带HT_1降温工艺与I_c关系研究  

EFFECTS OF HT_1 PROCESS FOR DECREASING TEMPERATURE ON CRITICAL CURRENT I_c IN Bi-2223/Ag TAPE

作　　者：刘奉生[1] 李成山[1] 纪平[1] 于泽铭[1] 郑慧玲[1] 熊晓梅[1] 郝清滨[1] 马荣超[1] 郑俊涛[1] 卢亚锋[1] 张平祥[1] 周廉[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016

出　　处：《低温物理学报》2005年第A02期801-806,共6页Low Temperature Physical Letters

摘　　要：热处理工艺对于Bi-2223／Ag超导带性能具有决定性作用，热处理过程中不适当的处理温度、保温时间以及在特定温区内不合适的升降温速率，都会导致Bi-2223／Ag带超导性能的降低．本文研究了在2223相基本生成之后第一次热处理（HT1）降温过程中影响临界电流Ic的温度范围和降温速率．实验证明，HT1的降温过程对Ic有着不可忽视的影响．在800℃～200℃范围内任何附加的保温都会使Ic降低，其中尤以710℃～350℃严重．在此温度范围内，于21％O2分压气氛下，当2223相成相率为～80％时，小于70℃／h的降温速率将使Ic明显下降．XRD的结果发现，较高Ic样品总是含有相对含量为1．8％左右的2212相，在Ic较低的样品中却没有发现2212相，只是3221相稍多．SEM揭示：HT1后经附加热处理的样品中，2223相微裂纹增多，所析出的CuOy尺寸增大而且分布不均匀，这些都造成2223相的连接性变差，使Ic降低．The temperature range and rate of decreasing temperature during first heat treatment （HT1） after 2223 phase was formed primarily have been investigated. The results show that the effect of rate of decreasing temperature on critical current Ic is remarkable. Any additional temperature keeping at ranges 200℃～800℃, especially 350℃～710℃, can result in decreasing Ic obviously. Furthermore, in the temperature range, at 21%O2 partial pressure, when 2223 phase formed is about 80% the rate of decreasing temperature less than 70℃/h will decrease Ic. The XRD results show that the samples with higher Ic contain 2212 phase about 1.8%, in contrast samples with lower Ic contain more 3221 phase than the former, but does not contain 2212 phase.

关 键 词：Bi-2223/Ag超导带 热处理 临界电流 

分 类 号：O511[理学—低温物理]