Title :
Comparison of Ba2YCu3O7-δ films on NdGaO3 and LaAlO
Author :
Phillips, Julia M. ; Siegal, M.P. ; Perry, C.L. ; Marshall, J.H.
Author_Institution :
AT&T Bell Lab., Murray Hill, NJ, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
The authors have studied the properties of 100-nm films of Ba2YCu3O7-δ (BYCO) grown on LaAlO 3(100) and NdGaO3(100) by coevaporation of Cu, Y, and BaF2 followed by a two-stage anneal ex situ. It is found that the structural properties of the films on both substrates are optimized when the maximum temperature of the anneal is 900°C, while the superconducting properties are slightly better if the maximum temperature does not exceed 875°C. Films on LaAlO3 can tolerate a longer time at the maximum annealing temperature than films on NdGaO3. Optimized BYCO films on NdGaO3 have substantially worse electrical and structural properties than those on LaAlO3. It is hypothesized that this is due to a reaction between Ga in the NdGaO3 and at least one of the constituents of the, BYCO film, probably Y
Keywords :
annealing; barium compounds; high-temperature superconductors; superconducting thin films; yttrium compounds; 100 nm; 875 degC; 900 degC; Ba2YCu3O7-δ; LaAlO; NdGaO3; electrical properties; films; high temperature superconductors; structural properties; superconducting properties; two-stage anneal; Annealing; Dielectric substrates; Dielectric thin films; Electrical resistance measurement; Electron emission; Furnaces; Magnetic field measurement; Superconducting films; Surface morphology; Temperature distribution;
Journal_Title :
Magnetics, IEEE Transactions on
