Title :
In-situ low-temperature growth of YBa2Cu3O 7-x films by reactive coevaporation
Author :
Tsuge, H. ; Matsukura, N.
Author_Institution :
NEC Corp., Ibaraki, Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
Epitaxial YBa2Cu3O7-x films were grown in situ by reactive coevaporation using a triple-hearth electron-beam gun system, in which a single electron beam is scanned over constituent metal sources. Superconducting properties were improved by using reactive oxygen species generated from an RF discharge during growth and cooling. Zero-resistance temperatures Tc(R=0) of 86-91 K and critical current densities of around 106 A/cm2 at 77 K were obtained over the entire MgO(100) substrate of 15×15 mm2. The c-axis-, a-axis-, and [110]-oriented films were selectively grown on MgO(100), SrTiO3(100), and SrTiO3(110), respectively, in a wide substrate temperature range with a crystallization temperature below 500°C. A film prepared on SrTiO 3(110) exhibited Tc(R=0)=80K even when the substrate temperature was as low as 475°C
Keywords :
barium compounds; critical current density (superconductivity); high-temperature superconductors; superconducting epitaxial layers; superconducting transition temperature; vapour phase epitaxial growth; yttrium compounds; (100) substrate; (110) substrate; 475 degC; 500 degC; 86 to 91 K; MgO; RF discharge; SrTiO3; YBa2Cu3O7-x films; critical current densities; crystallization temperature; epitaxial films; high temperature superconductors; in situ low temperature growth; reactive coevaporation; superconducting properties; triple-hearth electron-beam gun system; zero resistance temperatures; Cooling; Critical current density; Crystallization; Electron beams; Fault location; Radio frequency; Substrates; Superconducting epitaxial layers; Superconducting films; Temperature distribution;
Journal_Title :
Magnetics, IEEE Transactions on
