MOCVD of TlBaCaCuO Superconducting Thin Films: Structure - Property - ProcessingRelationships

摘要

Superconducting TlBaCaCuO films were fabricated using a three step process.Amorphous BaCaCuOF films were grown on MgO(100) single crystal substrates by metalorganic chemical vapor deposition at 500 C and 4 torr using fluorinated BETA-diketonate complexes of Ba, Ca, and Cu. The fluorine was stripped in wet O2 at 785 C and c-axis oriented Tl2Ba2CaCu2x films were formed by annealing in dry O2 between 850 and 900 C in the presence of TlxOy vapor. The best films showed onsets of superconductivity at 125 K and zero resistivity was achieved by 109 K. Surface resistivities an order of magnitude lower than gold at 17 GHz (77 K) and J sub c s as high as 1000 A/cm sq (90 K) were obtained with unpatterned films.