Title :
Role of oxygen pressure during deposition on the microwave properties of YBCO films
Author :
Rudman, D.A. ; Stork, F.J.B. ; Booth, J.C. ; Juang, J.Y. ; Vale, L.R. ; Beatty, G.J. ; Williams, C.I. ; Beall, J.A. ; Ono, R.H. ; Qadri, S.B. ; Osofsky, M.S. ; Skelton, E.F. ; Claassen, John H. ; Gibson, G. ; MacManus-Driscoll, J.L. ; Maide, N. ; Cohen, L
Author_Institution :
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
fDate :
6/1/1999 12:00:00 AM
Abstract :
We have studied the effect of oxygen pressure (PO/sub 2/) during pulsed laser deposition on the properties of YBCO films, with particular attention power microwave surface resistance R/sub s/. Above a threshold oxygen pressure the properties of the films are nearly independent of PO/sub 2/ during deposition and are typical of high quality YBCO films. The films made below this threshold pressure have increased disorder which produces a reduced T/sub c/ and an expanded c-axis lattice parameter. However, these films also have significantly reduced low temperature R/sub s/, which is likely a direct result of the increased scattering in these films. Preliminary Raman measurements show no increase in the Y-Ba cation disorder in these low PO/sub 2/ films, so that different disorder mechanism must be present.
Keywords :
barium compounds; high-frequency effects; high-temperature superconductors; pulsed laser deposition; superconducting thin films; yttrium compounds; Raman spectra; YBCO films; YBa/sub 2/Cu/sub 3/O/sub 7/; deposition; disorder mechanism; expanded c-axis lattice parameter; high temperature superconductor; microwave properties; microwave surface resistance; oxygen pressure; pulsed laser deposition; Lattices; Masers; Optical pulses; Power lasers; Pulsed laser deposition; Raman scattering; Surface emitting lasers; Surface resistance; Temperature; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
