High Critical-Current Density in the Heavily Pb-Doped Bi2Sr2CaCu2O8+
Superconductor: Generation of Efficient Pinning Centers
I. Chong,
Z. Hiroi,
*
M. Izumi,
J. Shimoyama,
Y. Nakayama,
K. Kishio,
T. Terashima,
Y. Bando,
M. Takano
Critical-current density (Jc) is a parameter
of primary importance for potential applications of high-temperature
copper oxide superconductors. It is limited principally by the
breakdown of zero-resistive current due to thermally activated flux
flow at high temperatures and high magnetic fields. One promising
method to overcome this limitation is to introduce efficient pinning centers into crystals that can suppress the flux flow. A marked increase in Jc was observed in
Bi2Sr2CaCu2O8+
(Bi-2212) single crystals doped with a large amount of Pb. By electron
microscopy, characteristic microstructures were revealed that probably
underlie the observed enhancement in Jc: thin
(10 to 50 nanometers), platelike domains having a modulation-free
structure appeared with spacings of 50 to 100 nanometers along the
b axis.
I. Chong, Z. Hiroi, M. Izumi, T. Terashima, Y. Bando, M. Takano,
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Japan.
J. Shimoyama, Y. Nakayama, K. Kishio, Department of Applied Chemistry,
University of Tokyo, Bunkyo-ku, Tokyo 113, Japan.
*
To whom correspondence should be addressed.