Bismuth strontium calcium copper oxide
Bismuth strontium calcium copper oxide (BSCCO, pronounced bisko), is a type of cuprate superconductor having the generalized chemical formula Bi2Sr2Can−1CunO2n+4+x, with n = 2 being the most commonly studied compound (though n = 1 and n = 3 have also received significant attention).
Further, because BSCCO has n = 1, 2 and 3 members, these naturally tend to accommodate low angle grain boundaries, so that indeed they remain atomically smooth.
[citation needed] Typically, precursor powders are packed into a silver tube, which is then extruded down in diameter.
This rises markedly with decreasing temperature so that many applications are implemented at 30–35 K, even though Tc is 108 K. Electrical power transmission : Electromagnets and their current leads : BSCCO as a new class of superconductor was discovered around 1988 by Hiroshi Maeda and colleagues[1] at the National Research Institute for Metals in Japan, though at the time they were unable to determine its precise composition and structure.
The n = 3 member proved quite elusive and was not identified until a month or so later by Tallon[7] et al. in a government research lab in New Zealand.
A key early development was to replace about 15% of the Bi by Pb, which greatly accelerated the formation and quality of Bi-2223.
BSCCO needs to be hole-doped by an excess of oxygen atoms (x in the formula) in order to superconduct.
Thus the application of pressure in Bi-2223 results in Tc rising to a maximum of about 123 K due to optimization of the two outer planes.
Even though BSCCO has a higher upper critical field than YBCO it has a much lower H* (typically smaller by a factor of 100)[11] thus limiting its use for making high-field magnets.
