Preparation of Bi2Sr2CaCu2O8+δ-YBa2Cu 3O7−δ Bilayer Films by Acetate Based Photosensitive Sol-Gel Method

Bi
₂
Sr
₂
CaCu
₂
O
_8+δ
(Bi-2212)/YBa
₂
Cu
₃
O
_7-δ
(YBCO) and YBCO/Bi-2212 heteroepitaxial bilayer films have been successfully prepared on LaAlO
₃
(LAO) monocrystalline substrates by acetate based photosensitive Sol-Gel method. Two superconducting transition steps in the R-T curves of YBCO/Bi-2212 and Bi-2212/YBCO bilayer films were clearly observed. The first transition step has the superconducting critical transition temperature (Tc) of 90.1-90.8 K and the superconducting transition width (ΔTc) of 2-2.2 K, and these values correspond to the Tc and ΔTc values of YBCO single film. The second transition step has the Tc of 80-84 K and the ΔTc of 4.6-5.2 K, and these values correspond to the Tc and ΔTc values of Bi-2212 single film. XRD results showed that YBCO/Bi-2212 and Bi-2212/YBCO bilayer films grow heteroepitaxially with good in-plane and out-of-plane growth texture.