摘要
从材科物理化学角度研究了T_c为110K的Bi_2 Sr_2 Ca_2 Cu_3 O_(10+δ)高温超导相(2223相)形成机理。结果表明,2223相是由Bi_2 Sr_2 Ca Cu_2 O_(2+δ)低温超导相(2212相)部分溶解后,在液相参与下反应而成。反应符合按成核生长机理进行的固相反应的JMA动力学关系。由于高、低温相间存在一定的三维晶体学关系,当形成速率较快时,可能导致2223相结构的局部不规整而影响其电磁性能,退火等处理可促进局部规整反应。依此较好地解释了相分析结果与电磁性能间的不一致,并提出了强化2223相形成的措施。
The forming mechanism of 2223 (To_c=110K, Bi_2 S_r2 Ca_2 Cu_3O_(10+d)) high-Tc superconducting phase in view of material physical chemistry is studied in the paper. It reveals that With the solubilization of part of 2212 phase, 2223 phase is formed by the solid reaction being carried out according to nucleating and growing mechanism in the presence of liquid phase, which conforms to JMA dynamics regularity. As the low-T_c and high-T_c phases have definite three-dimensional crystallographic relationship in crystal structure, the quickly forming speed of 2223 phase may lead to partial irregularity of 2223 phase structure, which affects its electric and magnetic properties. Annealing can promote topotactic reaction. Thus, the irregularity between the results of phase analysis and electric, magnetic properties can be explained, and the measures of consolidating 2223 phase can be determined.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1992年第4期342-346,共5页
Journal of The Chinese Ceramic Society
基金
浙江大学科学基金
关键词
超导体
铋系陶瓷
反应机理
high critical temperature superconductors
bismuth system ceramics, reaction me-chanism
