Yttrium-barium cuprate superconductors on titanium and rutile substrates

The applicability of titanium and titanium oxide as substrate material for coated conductors was investigated. Titanium metal was rolled to a thickness of 1 mm and mechanically polished. The surface of the titanium sheet was first oxidized at 870 °C for four hours in flowing oxygen yielding a dense oxide layer. The oxidized surface was mechanically polished. YBCO superconducting layers were applied to oxidized titanium and to rutile surfaces by screen printing. The samples were then annealed in flowing oxygen at 870 °C. The superconducting layers were characterized by X-ray diffraction, optical and electron microscopy and by electrical and magnetic measurements. The resulting superconducting layers were dense and showed critical temperatures of up to 92 K.