Fabrication of Tl-Ca-Ba-Cu-O superconducting thin films on LaAlO3 substrates

Abstract

For the first time, fabrication of high-temperature superconducting Tl-Ca-Ba-Cu-O (TlCaBaCuO) thin films on LaAlO3 substrates is reported. TlCaBaCuO thin films were deposited by rf magnetron sputtering of a single composite powder target in a pure argon plasma. The films were sintered in an excess thallium ambient at 850 °C for 15 min followed by a 30 min oxygen annealing at 750 °C. Scanning electron microscopy and x-ray diffraction results showed the smooth and highly c-axis oriented nature of the thin films. The temperature dependence of resistance showed the onset of critical transition temperature (Tc) at 114 K, and zero resistance at 103 K.

Effect of annealing temperature on the structural-microstructural and electrical characteristics of thallium bearing HTSC films prepared by chemical spray pyrolysis technique

“…Because of their high T c (~ 125 K) and high J c , they are readily amenable to operation at liquid nitrogen temperature (~ 77 K). Uptil now, various methods for the preparation of HTSC thin films such as electron beam evaporation (Ramesh et al 1990;Ginley et al 1998a,b;Sugise et al 1998), sputtering (Lengfellner et al 1989;Lin and Wu 1989;Subramanyam et al 1990;Saito et al 1991;Ichikawa et al 1998;Zhou et al 1998), laser ablation (Betz et al 1989;Johs et al 1989), thermal flash evaporation (Barboux et al 1988;Ece and Vook 1989;Verma et al 1989), chemical spray pyrolysis (Kawai et al 1987;Gupta et al 1988;Saxena et al 1988;DeLuca et al 1991;Verma et al 1992) and spin coating (Rice et al 1987) etc have been employed. Out of these techniques, the simple chemical process like spray pyrolysis and spin coating are economically viable.…”

Y-Ba-Cu-O Superconducting/GaAs Semiconducting Hybrid Circuits for Microwave Applications

“…The amplifier matching and dc bias networks were fabricated by rf magnctron sputtering a TBCCO film from a single composite powder target of TIzBaiCa2Cu30 x to a thickness of 3750,_ onto a 20 roll thick LaAIO 3 substrate [8]. Gold contact areas for wire bonding purposes were formed through a lift-off process and 2.5# m of silver was thermally evaporated on the opposite side of the substrate which acted as the ground plane.…”