Synthesis of porous high-temperature superconductors via a melamine formaldehyde sacrificial template

Nanostructured high-temperature superconductors YBa(2)Cu(3)O(6+δ) and Bi(2)Sr(2)CaCu(2)O(8+δ) were synthesised using a melamine formaldehyde sponge as a sacrificial template, via three solution-based approaches. In the case of YBa(2)Cu(3)O(6+δ), a modified Pechini method produced a material with a superconducting transition at 92 K and a specific surface area of 4.22 m(2) g(−1). Further analysis with Hg porosimetry determined that the sponge exhibited a porosity of 82%. In the case of Bi(2)Sr(2)CaCu(2)O(8+δ), this method produced a material that exhibited superconductivity at 86 K with a specific surface area of 9.62 m(2) g(−1). Hg-porosimetry determined that the BSCCO sponge exhibited a porosity of 78%