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本文采用顶部籽晶熔渗法(TSIG)成功制备出了不同过冷度下、不同保温时间的系列YBCO单畴超导块材;同时采用原位观察的方法,借助高温摄像技术实时记录了YBCO晶体的生长过程.通过对在不同过冷度、不同保温时间YBCO晶体生长形貌的分析和研究,结果表明:YBCO晶体起始外延生长温度为1008°C,单畴生长温度窗口为988°C–1008°C;在确定的过冷度下保温时,YBCO晶体的起始生长速率很快,最大平均生长速率达到0.95 mm h-1,之后,先快速衰减,然后逐渐趋于稳定;在YBCO晶体生长温区范围内,过冷度越大,生长速率越快,晶体生长的平均速率与过冷度之间的关系可以用Ra=a(△T)b公式来描述;YBCO晶体的瞬时生长速率在0.01–0.72 mm h-1之间,具有很大的波动性,但瞬时生长速率的平均值随过冷度的增大呈线性增加.这些结果对于进一步制备高质量的YBCO块材具有重要的指导意义.
In this paper, a series of YBCO single-domain superconducting blocks with different undercooling and different holding time were successfully prepared by top seed infiltration method (TSIG). At the same time, in situ observation was used to record YBCO The growth process of YBCO crystal was studied by the analysis of the growth morphology of YBCO crystal at different subcooling degrees and different holding time.The results show that the initial epitaxial growth temperature of YBCO crystal is 1008 ° C and the single-domain growth temperature window is 988 ° C -1008 ° C; YBCO crystal initial growth rate at a fixed undercooling temperature, the maximum average growth rate of 0.95 mm h-1, then quickly decay, and then gradually stabilized; YBCO The relationship between the average rate of growth and the degree of supercooling can be described by Ra = a (△ T) b in the temperature range of the crystal growth. The higher the undercooling and the faster the growth rate, the instantaneous growth of YBCO crystal The velocities range from 0.01-0.72 mm h-1 with great volatility, but the average of the instantaneous growth rates increases linearly with increasing undercooling.These results are important for the further preparation of high-quality YBCO blocks The guiding significance.