Es. Reddy et al., Single-domain YBa2Cu3Oy thick films and fabrics prepared by an infiltration and growth process, J MATER RES, 16(4), 2001, pp. 955-966
An infiltration and growth process has been developed to produce single-dom
ain YBa2Cu3Oy(123) as thick films on various substrates or as self-supporti
ng fabrics. Commercially available Y2O3 cloths of square woven or satin wov
en structure were infiltrated with liquid phases from a suitable source con
taining barium cuprates and copper oxides and subsequently converted into Y
2BaCuO5(211) and -123 phases by a series of distinct peritectic reactions.
Depending on the final form of 123, the Y2O3 cloth was either clamped firml
y at corners to produce a self-supporting 123 fabric or placed on a suitabl
e substrate to result in a thick film coating of 123. The source material f
or the liquid phase being in the form of solid blocks was placed at corners
of the cloth in the case of free-standing 123 fabrics. In case of the thic
k film configuration the liquid phase powder was spread on the surface of t
he Y2O3 cloth. A small c-axis-oriented MgO or Nd(123) seed was used to gene
rate an oriented 123 domain in the infiltrated fabric. The solidification p
rocess was optimized to transform the entire Y2O3 fabric into a single-doma
in 123, The microstructure of the single domain was optimized in terms of 2
11 size and content for high J(c). A detailed description of the process, t
he growth mechanism, the resulting microstructures was given, and basic sup
erconducting properties of the new form of 123 are briefly discussed.