熔融慢冷生长YBCO超导体中方晶的晶粒生长取向的观察  

The Orservat Of Rectangular Crystal In Large Bulk YBCO Superconductor By Melting Slowly Cooling Process

作　　者：杨万民[1] 汪京荣[1] 张翠萍[1] 李建平[1] 王天成[1] 周廉[1] 

机构地区：[1]西北有色金属研究院

出　　处：《低温与超导》1994年第4期19-24,共6页Cryogenics and Superconductivity

摘　　要：采用熔融慢冷工艺制备的大块ＹＢＣＯ超导体中．超导相晶畴多以长方晶（简称方晶）的形式存在，该文通过对该类样品的ＳＥＭ观测．发现方晶被沿其对角线的两条轨迹分成四个畴区．两条对角线的夹角一般约７８℃；方晶中四个畴区的晶粒均呈片状生长，各晶片相互平行，且平行于ａｂ面．垂直于ｃ轴，宏观上平行于方晶的短边，而垂直于其长边，其晶片均垂直于样品表面且向其内部生长，这种由超导晶片堆积成的层状结构，充分说明了ＹＢＣＯ超导体织构的各向异性，由此则决定了其性能的各向异性；方晶中的裂纹基本上平行于ａｂ面，垂直于ｃ轴．并对其产生原因进行了分析。In a large bulk YBCO superconductor by melting slowly cooling process,the superconductingphase appears mainly as a rectangular crystal with an across-shaped trace on the surface. This paper aimed at the superconducting grain's orientation in the rectangular crystal. Using scaningelectron microscope, we observed the cross section and vertical section of the rectangular crystal,and conclude that 1)A rectangular crystal is separated into four parts by the across-shaped trace,the smaller angle between the trace is about 78°;The grains grown direction parallel to each otherin the four parts,and parallel to the direction of the smaller length of the crystal;The grains grewvertically towards inside the sample; The direction of cracks parallel mainly to the ah-plane andvertical to the c-axis in the rectangular cristal.

关 键 词：熔融生长 YBCO超导体 长方体晶畴 晶粒取向 

分 类 号：O514[理学—低温物理] O782.9[理学—物理]