Increased irreversibility line by precipitate pinning in the Bi-Sr-Ca-Cu-O system
Increased irreversibility line by precipitate pinning in the Bi-Sr-Ca-Cu-O system
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Bi-Sr-Ca-Cu-O 系统中沉淀物钉扎增加了不可逆线
DOI：
10.1088/0953-2048/5/2/007
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
S. McFarland
中科院分区：
文献类型：
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作者：
S. Salem;D. Shi;S. McFarland
作者测量了高磁场（高达7 T）下不同微结构的Bi-Sr-Ca-Cu-O样品的磁不可逆性H*（T）。我们发现，在具有大量晶体缺陷的Bi_2Sr_2Ca_3Cu_4Ox（2234）样品中，H ~*（T）显著增加，包括严重的晶格畸变和富钙和富铜沉淀。他们认为，晶格畸变可能会影响各向异性的程度和铜-O层之间的约瑟夫森耦合，这反过来又增强了Bi-Sr-Ca-Cu-O系统中的不可逆性。在8 kG和40 K下，在具有许多缺陷的2234样品中获得了8 × 104 A cm-2的临界电流密度Jc，而在具有均匀微观结构的近化学计量比Bi_2Sr_2Ca_2Cu_3 O_x（2223）样品中，在相同的温度和电场下，Jc显著下降。
The authors measured magnetic irreversibility, H*(T), in liquid-quenched Bi-Sr-Ca-Cu-O samples with various microstructures at high applied field (up to 7 T). We found that H*(T) is considerably increased in the Bi2Sr2Ca3Cu4Ox (2234) sample with a large number of crystal defects, including severe lattice distortion and calcium and copper rich precipitates. They argue that the lattice distortion may affect the degree of anisotropy and the Josephson coupling between the Cu-O layers, which in turn enhance the irreversibility in the Bi-Sr-Ca-Cu-O system. A critical-current density, Jc, of 8*104 A cm-2 at 8 kG and 40 K was obtained in the 2234 sample with many defects, while the Jc dropped significantly at the same temperature and field in the near stoichiometry Bi2Sr2Ca2Cu3Ox (2223) sample with a uniform microstructure.