High-T_c superconductivity: New applications of ferroelectrics at microwave frequencies

Abstract

The initial success in high-T _c superconductivity applications at microwaves leads to the creation of new branch in microwave electronics operating at liquid nitrogen temperature. In this connection one should reconsider the behaviour of nonlinear dielectrics at microwaves. The characteristics of a capacitor in the form of trilayer structure YBa₂Cu₉O_7−x/(Ba_xSr_1−x)TiO₉/YBa₂Cu₉O_7−x are discussed. The crucial influence of oxygen stoichiometry on the structure properties is assumed. The layered structures including non-linear dielectrics could be used as a basis for devices with voltage control of the microwave circuit parameters.

Key Words:

• high-T_c superconductivity
• non-linear dielectrics
• voltage controllable capacitor
• trilayer YBa₂Cu₉O_7−x(Ba_xSr_1−x)TiO₉/YBa₂Cu₉O_7−x structure
• microwaves