(001) grain boundaries and critical currents
M Essers; P H Kes; W T Fu; H W Zandbergen; M Essers; Kamerlingh Onnes Lab., Leiden Univ., Netherlands; P H Kes; Kamerlingh Onnes Lab., Leiden Univ., Netherlands; W T Fu; Kamerlingh Onnes Lab., Leiden Univ., Netherlands; H W Zandbergen; Kamerlingh Onnes Lab., Leiden Univ., Netherlands
Журнал:
Superconductor Science and Technology
Дата:
1993-04-01
Аннотация:
Magnetization measurements and high resolution electron microscopy (HREM) have been carried out on the series Y<sub>1-x</sub>Ca<sub>x</sub>Ba<sub>2-x</sub>La<sub>x</sub>Cu<sub>3</sub>O<sub>7- delta </sub> to determine the correlation between critical current and (001) grain boundaries. Substituting Ca for Y reduces the fraction of (001) grain boundaries and increases the fraction of grain boundaries other than (001). The critical current increases linearly with the fraction of clean grain boundaries other than the (001) boundaries. It is concluded that the (001) grain boundaries in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub> act as weak links. It is argued that the atomic structure of the interface is responsible. In addition it is observed that the intragrain critical current decreases with increase of x.
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