J. Phys. IV France 11 (2001) Pr11-41-Pr11-45
Epitaxial YBa2Cu3O7-8/SrTiO3 heterostructures grown by pulsed laser deposition for voltage agile microwave filter applicationsK. Bouzehouane, P. Woodall, B. Marcilhac, A.N. Khodan, D. Crété, E. Jacquet, J.C. Mage and J.P. Contour
Unité Mixte de Physique, CNRS/Thales, 91404 Orsay, France
The performance of tunable microwave devices based on heteroepitaxial YBa2Cu3Ox/SrTiO3 films on (001) LaAlO3 substrate has been evaluated. It has been ascertained that 'out-of-plane' SrTiO3 lattice parameter is the relevant factor in determining both the agility and dielectric loss of the SrTiO3 layers. After high temperature annealing (1100 °C, 1 atm O2), only SrTiO3 layers deposited under low oxygen pressure (˜ 10-5 Torr) show an appreciable reduction of the dielectric losses whilst maintaining high agility. Annealed samples exhibit voltage independent losses of ˜ 5.10-3 simultaneously with 55% dielectric agility at 6 GHz and 77K.
© EDP Sciences 2001