Metalorganic chemical vapor deposition of Tl2Ba2CaCu2Ox superconducting thin films using fluorinated β-diketonate source reagents

Superconducting Tl2Ba2CaCu2Ox films were fabricated using a three-step process. Amorphous BaCaCuOF films were deposited on MgO(100) single-crystal substrates by metalorganic chemical vapor deposition at 500 °C using fluorinated β-diketonate complexes of Ba, Ca, and Cu. The fluorine was stripped in wet oxygen at 785 °C and c-axis oriented Tl2Ba2CaCu2Ox films were then formed by annealing in dry at 870 °C in the presence of Tl2O3/Ba2Ca2CuN3Ox pellets. The best films showed onsets of superconductivity at 125 K and zero resistivity was achieved by 108 K. Critical current densities as high as 104 A/cm2 were obtained at 90 K.