熔融织构YBCO块材表面俘获磁场研究  

STUDY OF TRAPPED MAGNETIC FIELD ON THE SURFACE OF MELT TEXTURED YBCO DISKS

作　　者：焦玉磊[1] 任洪涛[1] 肖玲[1] 郑明辉[1] 

机构地区：[1]北京有色金属研究总院

出　　处：《低温物理学报》1998年第1期56-61,共6页Low Temperature Physical Letters

摘　　要：用霍尔探头系统在７７Ｋ温度下，测量了顶部籽晶技术制备的熔融织构ＹＢＣＯ超导块在场冷后的表面俘获磁场的三维分布，并画出了其二维等高线图．结果表明，对单畴样品，俘获磁场分布图仅有一个峰，其二维等高线基本呈中心轴对称分布．在约０．５Ｔ的磁化场下，测得的最大俘获场为１７０ｍＴ．而对非单畴样品，俘获场的三维分布不是单峰，其二维等高线分布与样品晶畴的表观形貌相一致，即ａｂ面与样品表面平行的大畴区域俘获场最大，其余部分的俘获场较小．因此，可以认为由俘获场的测量能够检测样品内的结晶状况，一般情况下，单峰对应单畴，多峰对应多畴，在多畴间存在弱连接的大角晶界．Abstract The spatial distribution of trapped magnetic field on the surface of melt textured YBCO disks prepared by a top seeded technique has been measured by using a Hall probe in the field cooled at 77K. The result has been mapped as a three dimentional distribution and a two dimentional contour graph for each sample. It exhibits only one peak in the trapped field distribution of the disk with single domain, and the shape of the peak has a central axial symmetry. The maximum value of trapped field is approximately 170mT with 0.5T applied field. But more than one peak occur for the disk with multi domain, as corresponding to the morphology of domains on its surface, and the trapped field is the highest in the largest domain with ab plane parallel to the surface of sample. Therefore, certain microstructure of samples can be detected by measuring trapped magnetic field distribution. In general, a single peak corresponds to a single domain, and many peaks correspond to multi domain, in which there are large angle grain boundaries with weak link between these domains.

关 键 词：熔融织构 YBCO 块材表面 俘获磁场 

分 类 号：TM262.014[一般工业技术—材料科学与工程]