Title :
Inductive measurements of /spl lambda/(T) of bare YBCO films and the proximity effect in YBCO/normal metal bilayers
Author :
Schneider, C.W. ; Somekh, R.E. ; Evetts, J.E. ; Walker, D.J.C. ; Watson, I.M. ; Baudenbacher, F. ; Mao, S.N. ; Xi, X.X. ; Li, Q. ; Chuhee Kwon ; Venkatesan, T. ; Humphreys, R.G. ; Chew, N.G. ; Gross, R. ; Beck, A.
Author_Institution :
Dept. of Mater. Sci. & Metall., Cambridge Univ., UK
fDate :
6/1/1995 12:00:00 AM
Abstract :
Inductive measurements were performed on YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) films and superconducting/normal metal bilayers using Au, PrBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// and (Y/sub 0.4/Pr/sub 0.6/)Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// as normal material in order to investigate their screening properties between T/sub c/ and 2.2 K. YBCO films were prepared using high pressure dc and hollow cathode sputtering, laser ablation, MOCVD and reactive thermal coevaporation and the penetration depth, /spl lambda/, and the c-axis lattice parameter measured. Comparison of the temperature dependence of the superfluid density, n/sub s/(T), for the YBCO films showed a significant difference in the shape of n/sub s/(T) depending on the deposition method used. This could have implications for preparing stable passive microwave devices. We have also demonstrate that SN-bilayers, using YBCO as the superconductor, exhibit an enhanced screening over the entire temperature range compared with bare YBCO films.<>
Keywords :
barium compounds; high-temperature superconductors; inductance; lattice constants; penetration depth (superconductivity); proximity effect (superconductivity); superconducting thin films; yttrium compounds; (Y/sub 0.4/Pr/sub 0.6/)Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta//; 2.2 to 89 K; Au; DC sputtering; MOCVD; PrBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; YBCO films; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; YBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/-Au; YBa/sub 2/Cu/sub 3/O/sub 7/-PrBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/-Y/sub 0.4/Pr/sub 0.6/Ba/sub 2/Cu/sub 3/O/sub 7/; hollow cathode sputtering; inductive measurements; laser ablation; lattice parameter; passive microwave devices; penetration depth; proximity effect; reactive thermal coevaporation; screening; superconducting/normal metal bilayers; superfluid density; Gold; Inorganic materials; Optical materials; Performance evaluation; Pressure measurement; Proximity effect; Superconducting films; Superconducting materials; Superconducting microwave devices; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
