Superconducting YBCO (Tc(0) $equal$ 92 K) and Bi-2223 (Tc(0) $equal$ 110 K) thick films on polycrystalline Ba2LaHfO5.5: a new perovskite ceramic substrate

Abstract

Ba 2 LaHfO 5.5 (BLHO) has been developed as a new ceramic substrate suitable for both YBa 2 Cu 3 O 7-δ (YBCO) and (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O x (Bi-2223) superconductors. BLHO has a complex cubic perovskite (A 2 BB O 6 ) structure with lattice constant a = 8.395 Å. The DTA studies revealed that there is no phase transition occurring in BLHO material in the temperature range of 30-1200 • C. The dielectric constant and loss factor values of BLHO are in a range suitable for its use as a substrate material for microwave applications. YBCO and Bi-2223 superconductors do not show any detectable chemical reaction with BLHO even under extreme processing conditions. The thick films of YBCO dip-coated on polycrystalline BLHO substrate gave T c (0) of 92 K and J c of ∼1.1 × 10 4 A cm −2 . The Bi-2223 thick films dip-coated on polycrystalline BLHO substrate gave T c (0) of 110 K and J c of ∼3 × 10 3 A cm −2 . The YBCO and Bi-2223 thick films had excellent adhesion on polycrystalline BLHO substrate.

Insulation coating of silver tapes using an organometallic solution of Zr and Ca for application to Bi-based superconductors

“…Electrical insulation of superconducting elements is required in diverse applications of superconductivity [7][8][9][10]. It is most likely that the solution to the insulation problem for superconductors will differ for each specific application depending on many factors such as the processing route, operating conditions and conductor type, size and shape [11][12][13].…”