TY - JOUR
T1 - Microstructure and properties of Cu-rich 123
T2 - Part II. Homogeneous copper and high magnetic Jc
AU - Zhang, J. P.
AU - Li, D. J.
AU - Boldt, C.
AU - Plass, R.
AU - Dravid, V.
AU - Marks, L. D.
AU - Sodonis, A.
AU - Wolbach, W.
AU - Chabala, J. M.
AU - Levi-Setti, R.
AU - Lin, Chun-Hsiung
AU - Eades, J. A.
PY - 1993/6
Y1 - 1993/6
N2 - Copper- and yttrium-rich YBa2Cu3O7 bulk superconductors have been prepared by mixing copper oxide or yttrium oxide in nitric acid and adding the solution to premade stoichiometric YBa2Cu3O7 followed by annealing. In contrast to materials made by mixing oxide powders, both samples contain copper-rich defects spread homogeneously throughout the grains, either small platelet copper oxide precipitates or bundles of planar defects (Cu-O double planes). These materials also show large magnetic hysteresis at 77 K, comparable to the results obtained from decomposed YBa2Cu4O8. This implies that small copper oxide precipitates and bundles of planar defects are strong flux pinners, and indicates a processing route to producing large amounts of strongly intragranular pinned superconductors. However, the materials also show clean grain boundaries, so an equally valid interpretation is that there is a substantial component of intergranular superconductivity in field, enhancing the effective circuit size to a value far larger than the grain size.
AB - Copper- and yttrium-rich YBa2Cu3O7 bulk superconductors have been prepared by mixing copper oxide or yttrium oxide in nitric acid and adding the solution to premade stoichiometric YBa2Cu3O7 followed by annealing. In contrast to materials made by mixing oxide powders, both samples contain copper-rich defects spread homogeneously throughout the grains, either small platelet copper oxide precipitates or bundles of planar defects (Cu-O double planes). These materials also show large magnetic hysteresis at 77 K, comparable to the results obtained from decomposed YBa2Cu4O8. This implies that small copper oxide precipitates and bundles of planar defects are strong flux pinners, and indicates a processing route to producing large amounts of strongly intragranular pinned superconductors. However, the materials also show clean grain boundaries, so an equally valid interpretation is that there is a substantial component of intergranular superconductivity in field, enhancing the effective circuit size to a value far larger than the grain size.
UR - http://www.scopus.com/inward/record.url?scp=0027609574&partnerID=8YFLogxK
U2 - 10.1557/JMR.1993.1232
DO - 10.1557/JMR.1993.1232
M3 - Article
AN - SCOPUS:0027609574
SN - 0884-2914
VL - 8
SP - 1232
EP - 1239
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 6
ER -