三个不同温区下影响Bi_2Sr_2CaCu_2O_y单晶抗磁转变宽度因素的研究(英文)  

INVESTIGATION ON FACTORS AFFECTING DIAMAGNETIC TRANSITION WIDTH OF SINGLE CRYSTAL Bi 2Sr 2CaCu 2O y IN THREE ANNEALING TEMPERATURE ZONES

作　　者：赵小如[1,2] 吴文彬 孙学峰[1,2] 赵霞 赵芸[1,2] 张军 周贵恩[1,2] 李晓光[1,2] 

机构地区：[1]中国科学技术大学材料科学与工程系 [2]安徽机电学院

出　　处：《低温物理学报》1998年第1期34-40,共7页Low Temperature Physical Letters

摘　　要：本文研究了三个不同退火温区下（低于４５０℃、４５０～７００℃和高于７００℃）影响Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏｙ单晶抗磁转变宽度的因素．发现普遍被接受的在７００℃以下退火温区的分界线并不明确．ΔＴｃ的变化强烈依赖于退火条件，即使在２５０℃的较低退火温度下，Ｔｃ和ΔＴｃ也可以通过快速淬火而得到显著改善．然而在７００℃以上、不同条件下退火均得到较宽的ΔＴｃ与已有的报道是一致的，这可能是Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏｙ单晶的本征行为．以上结果可以用额外氧的含量和位置、阳离子迁移引起的结构调整来解释．Abstract An investigation on the factors affecting the diamagnetic transition width of single crystal Bi 2Sr 2CaCu 2O y has been conducted in three annealing temperature zones (below 450℃, 450~700℃, and above 700℃) related to Δ T c . It is found that under annealing below 700℃, the demarcation line of annealing temperature zone accepted generally by previous investigators is not clear. The variations of Δ T c depend strongly on the annealing conditions. Even at much lower annealing temperature 250℃, the T c and Δ T c can also be improved dramatically by quick quenching. However, annealing in different conditions above 700℃, the slight broader Δ T c which is in good agreement with published reports, may be intrinsic for the Bi 2Sr 2CaCu 2O y crystals involving in the annealing process. These results can be explained by the content and position of excess oxygen, and the structural modification caused by the mobility of cations.

关 键 词：退火温区 超导体 BSCCO 单晶 抗磁转变宽度 

分 类 号：TM262.01[一般工业技术—材料科学与工程]