Title :
Epitaxial YBa2Cu3O7-δ/SrTiO 3 heterostructures grown on LaAlO3 substrate by pulsed laser deposition for voltage tunable microwave filter applications
Author :
Woodall, P. ; Bouzehouane, K. ; Marcilhac, B. ; Crété, D.G. ; Jacquet, E. ; Mage, J.C. ; Contour, J.P.
Author_Institution :
CNRS, Thomson-CSF, Orsay, France
fDate :
3/1/2001 12:00:00 AM
Abstract :
The performance of microwave devices containing electrically tunable layers of strontium titanate has been evaluated for samples produced by pulsed laser ablation over a range of deposition temperatures on (001) LaAlO3 substrate. At zero bias the samples which exhibited the highest agility also exhibited the highest loss. It has been observed that the SrTiO3 lattice parameter is the relevant parameter in determining both the frequency agility of the sample and its dielectric loss. Furthermore, it was seen that whilst the SrTiO3 lattice parameter is dependent on deposition temperature, it has a maximum, and that samples grown at higher/lower temperatures around this maximum exhibit similar electrical properties for similar lattice parameter. A sample was then processed by a high temperature annealing of the SrTiO3 layer prior to YBCO deposition and it was found that dielectric loss is reduced over the whole range of agility without deterioration of the frequency agility
Keywords :
annealing; barium compounds; dielectric losses; frequency agility; high-temperature superconductors; lattice constants; microwave filters; pulsed laser deposition; strontium compounds; superconducting epitaxial layers; superconducting filters; superconducting microwave devices; yttrium compounds; LaAlO3; LaAlO3 substrate; YBa2Cu3O7-δ/SrTiO3 epitaxial heterostructure; YBa2Cu3O7-SrTiO3; dielectric loss; electrical properties; frequency agility; high temperature annealing; lattice parameter; pulsed laser deposition; voltage tunable microwave filter; Dielectric losses; Dielectric substrates; Frequency; Lattices; Microwave devices; Pulsed laser deposition; Strontium; Temperature dependence; Temperature distribution; Tunable circuits and devices;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
