Preparation of Epitaxial YBCO Films by a Novel Excimer-Laser-Assisted MOD

Abstract

Epitaxial YBa 2 Cu 3 O 7 (YBCO) films were prepared on cerium oxide-buffered (40 nm) -cut single-crystal sapphire ( Al 2 O 3 ) substrates by a novel excimer-laser-assisted metalorganic deposition (ELAMOD). Laser irradiation after application of a fluorine-free ingredient solution onto the substrates revealed to have the advantages of shorter heating (prefiring and heat-treatment) time and higher superconducting current density ( c ). The c in excess of 5 MA cm 2 was measured by an inductive method at 77.3 K. The laser irradiation is considered to produce a desirable precursor, in which three metal components are well-mixed in short time. The x-ray diffraction measurement of the irradiated area clearly showed a complete -axis oriented YBCO and no impurity phase, whereas -axis oriented YBCO was also observed in the area without irradiation. The ratio of the -axis component decreased with an increase of the laser irradiation.

Effects of backside irradiation on Jc properties of YBCO films prepared by excimer-laser-assisted MOD (ELAMOD)

“…In the conventional ELAMOD (surface irradiation) the area without laser irradiation generally show no-J c properties, in other words, the J c values, if any, are under the limit of detection. The decomposition of metal-organic ingredients in the area without laser irradiation is presumed to be insufficient during the short-time prefiring in ELAMOD, resulting in no superconducting behavior [1,2]. On the other hand in ELAMOD using backside irradiation in this study, the area without laser irradiation also showed relatively high-J c values (2-5 MA/cm 2 ) as shown in Fig.…”

“…An excimer-laser-assisted metal-organic deposition (ELAMOD) method has been developed for preparation of high-J c YBa 2 Cu 3 O 7Ày (YBCO) films [1,2]. In the process, a fluorine-free metal acetylacetonate-based coating solution is spin-coated onto a CeO 2 -buffered r-cut sapphire (CbS) substrate.…”

Ultrafast Epitaxial Growth Kinetics in Functional Oxide Thin Films Grown by Pulsed Laser Annealing of Chemical Solutions

“…Tsuchiya et al have reported successful epitaxial growth with oxides like VO 2 , perovskite manganites (LMO, LSMO), Pb(Zr,Ti)O 3 and YBa 2 Cu 3 O 7 using UV excimer lasers. [27][28][29][30][31][32] In addition, we have also reported growth of epitaxial oxides like Ce 0.9 Zr 0.1 O 2-y and Ba 0.8 Sr 0.2 TiO . 33, These works have proposed different approaches to investigate the fundamental thermodynamic and kinetic principles of laser crystallization of CSD films.…”

Preparation of superconducting films by metal organic deposition

“…Manufacture of microwave filter on a 2 cm × 2 cm LaAlO 3 substrate and verification of filter performance [40] b. Achievements of YBCO deposition on a 5 cm diameter LaAlO 3 substrate and low surface resistance [41] c. Achievements of double-sided YBCO deposition on a 5 cm diameter CeO 2 /sapphire substrate and low surface resistance [42] d. Possibilities of YBCO deposition by excimer-laserassisted MOD (ELAMOD) and concurrent patterning [43] (2) Application to wire rods and tapes The YBCO superconducting wires and tapes with long length and thickness were achieved by chemical vapor deposition (CVD) and TFA-MOD using trifluoroacetate (TFA) as the raw material . The MOD method discussed in this research is called the fluorine free (FF) MOD method since it does not include harmful fluorine in the raw material, and is expected to become a manufacturing method for superconducting wire rods and tapes at low cost and low environmental load.…”