An enhancement in structural and superconducting properties of Bi2212 epitaxial thin films grown by the Pechini sol–gel method

Bi₂Sr₂CaCu₂O_8+δ (Bi2212) superconducting thin films were prepared by the Pechini sol–gel method using nitrates as reactants. The precursor sol was deposited on SrTiO₃(001) single-crystal substrates via the spin-coating method, and the results revealed the lowering of the Bi2212 phase-transition temperature; meanwhile the sintering time was significantly reduced. According to this investigation, the phase purity and crystallinity of Bi2212 thin films were obviously improved owing to the stable gel mechanism; the T_c,onset transition temperature value of the pure c-axis Bi2212 thin films rose to about 95 K.