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.