High J(c) in a biopolymer-mediated synthesis of YBa2Cu3O7-delta

Templated syntheses of YBCO phases have become ever more popular, owing to their fine control over phase purity and/or crystal morphology. Biological materials have recently been successfully used as templates owing to their ease of use. Here we show that the high temperature superconducting material YBa2Cu3O7-delta can be synthesized successfully using the biopolymer xylan, leading to a greatly improved critical current density in the final product. This pronounced increase is due to the control of crystallization by the biopolymer in the early stages of the synthesis, leading eventually to well-connected, plate-like crystallites of the superconducting phase.