Title :
Ten-fold tunability of the permittivity of Ba/sub 1-x/Sr/sub x/TiO/sub 3/ in epitaxial multilayers with (Y/Nd)Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta//
Author :
Boikov, Yu.A. ; Ivanov, Z.G. ; Claeson, T.
Author_Institution :
Dept. of Phys. & Eng. Phys., Chalmers Univ. of Technol., Goteborg, Sweden
fDate :
6/1/1999 12:00:00 AM
Abstract :
Dielectric properties of 400-600 nm thick epitaxial layers of SrTiO/sub 3/ and Ba/sub 0.9/Sr/sub 0.1/TiO/sub 3/, inserted between YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// or NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// electrodes, were investigated as functions of temperature and electric field. The electric field response of the dielectric permittivity of the ferroelectric layer correlated with the Curie point and was considerably higher with Nd based than with Y based superconducting electrodes. Insertion of thin buffer layers improved the tunability and decreased the microwave losses of the Ba doped dielectric.
Keywords :
barium compounds; ferroelectric Curie temperature; ferroelectric thin films; high-temperature superconductors; multilayers; neodymium compounds; permittivity; strontium compounds; superconducting epitaxial layers; yttrium compounds; Ba/sub 0.9/Sr/sub 0.1/TiO/sub 3/; Ba/sub 1-x/Sr/sub x/TiO/sub 3/; Curie point; NdBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; NdBa/sub 2/Cu/sub 3/O/sub 7/; SrTiO/sub 3/; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//; YBa/sub 2/Cu/sub 3/O/sub 7/; buffer layer; dielectric properties; electric field response; epitaxial multilayer; ferroelectric layer; microwave loss; permittivity; superconducting electrode; tunability; Dielectric losses; Electrodes; Epitaxial layers; Ferroelectric materials; Neodymium; Permittivity; Strontium; Superconducting epitaxial layers; Superconducting microwave devices; Temperature;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
