Ferroelectric/superconductor heterostructures

• Published in: Ferroelectrics Vol. 264; no. 1; pp. 111 - 116
• Main Authors: Hu, Wen-fei, Shi, D. X., Wang, T. S., Liu, W., Zhao, X. J., Peng, W., Lei, C., Chen, Y. F., Li, Lin
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2001
• Subjects: crack; ferroelectric; heterostructure; pulsed laser deposition; superconductor
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150190108008555

The reoccurrence of cracks have been found on the surfaces of epitaxial c-axis YBa 2 Cu 3 O 7-δ (YBCO) films grown on the vicinal SrTiO 3 substrates by pulsed laser deposition. At an optimum oxygen annealing condition, there are always cracks on the step-terrace surface of the YBCO films. Crack formation is attributed to the confinement of {110} mirror twinning induced by the anisotropic vicinal interfacial strain and the stress induced by the tetragonal-to-orthorhombic(T-O) phase transition of YBCO film. By use of vicinal SrTiO 3 substrates of with small tilting angle(1°−3°) from (001) toward [010] and reduction of the oxidation pressure to 80Pa for T-O phase transition YBCO films with smooth surface was formed, but the films are superconducting at 60K.