Microwave conductivity of laser ablated YBa2Cu3O(7-delta) superconducting films and its relation to microstrip transmission line performance
Abstract
The discovery of high temperature superconductor oxides has raised the possibility of a new class of millimeter and microwave devices operating at temperatures considerably higher than liquid helium temperatures. Therefore, materials properties such as conductivity, current density, and sheet resistance as a function of temperature and frequency, possible anisotropies, moisture absorption, thermal expansion, and others, have to be well characterized and understood. The millimeter wave response of laser ablated YBa2Cu3O(7-delta)/LaAlO3 thin films was studied as a function of temperature and frequency. In particular, the evaluation of their microwave conductivity was emphasized, since knowledge of this parameter provides a basis for the derivation of other relevant properties of these superconducting oxides, and for using them in the fabrication of actual passive circuits. The microwave conductivity for these films was measured at frequencies from 26.5 to 40.0 GHz, in the temperature range from 20 to 300 K. The values of the conductivity are obtained from the millimeter wave power transmitted through the films, using a two fluid model.
- Publication:
-
AMSARTS 1990: Advanced in Materials Science and Applications of High Temperature Superconductors
- Pub Date:
- January 1991
- Bibcode:
- 1991amsa.nasa..261B
- Keywords:
-
- Circuits;
- Current Density;
- High Temperature Superconductors;
- Microstrip Transmission Lines;
- Microwaves;
- Superconducting Films;
- Superconductors;
- Thin Films;
- Anisotropy;
- Current Sheets;
- Fabrication;
- Frequencies;
- Lasers;
- Liquid Helium;
- Microwave Equipment;
- Millimeter Waves;
- Moisture;
- Operating Temperature;
- Oxides;
- Thermal Expansion;
- Solid-State Physics