Title :
Novel approach to microcrack-free thick YBa2Cu3O7-δ films on r-cut sapphire buffered with CeO2
Author :
Nie, Jia Cai ; Yamasaki, Hirofumi ; Nakagawa, Yoshihiko ; Develos-Bagarinao, Katherine ; Murugesan, Mariappan ; Obara, Haruhiko ; Mawatari, Yasunori
Author_Institution :
Energy Technol. Res. Inst., Nat. Inst. of Adv. Ind. Sci. & Technol., Tsukuba, Japan
fDate :
6/1/2005 12:00:00 AM
Abstract :
Stoichiometric YBa2Cu3O7-δ (YBCO) films were fabricated by pulsed laser deposition on deliberately miscut Al2O3 (11_02) buffered with CeO2. Atomic force microscopy observations demonstrated that 600 nm-thick YBCO films were microcrack-free. Characterization of the films revealed a porous morphology, consisting of interconnected islands and deep holes (pores). This feature is considered as one of the sources contributing to the strain-relieving mechanism responsible for the increase in film thickness without microcracking. We observed Tc=90±0.5 K, Jc (77.3 K, 0 T)=1.5-2.0×106 A/cm2, and Jct (77.3 K, 0 T)∼120 A/cm. In addition, this new approach, using the deliberately miscut sapphire as a substrate for YBCO, is also applicable to other kinds of deposition techniques.
Keywords :
atomic force microscopy; barium compounds; critical current density (superconductivity); microcracks; pulsed laser deposition; stoichiometry; thick films; yttrium compounds; 600 nm; Al2O3; CeO2; YBa2Cu3O7; atomic force microscopy; critical current density; deposition technique; microcrack-free; miscut sapphire; porous morphology; pulsed laser deposition; stoichiometry; thick YBCO films; Atomic force microscopy; Capacitive sensors; Cooling; Fault current limiters; Lattices; Optical pulses; Pulsed laser deposition; Substrates; Superconducting microwave devices; Yttrium barium copper oxide; Critical current density; deliberately miscut sapphire; microcrack-free; thick YBCO film;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2005.848681
