Microwave surface resistance of magnetron-sputtered Tl-Ba-Ca-Cu-O films on silver substrates

• Published in: Applied physics letters 1990-05, Vol.56 (21), p.2147-2149
• Main Authors: COOKE, D. W, GRAY, E. R, ARENDT, P. N, REEVES, G. A, HOULTON, R. J, ELLIOTT, N. E, BROWN, D. R
• Format: Article
• Language: English
• Subjects: 360204 > Ceramics, Cermets, & Refractories-- Physical Properties; ALKALINE EARTH METAL COMPOUNDS; AMPLIFIERS; BARIUM COMPOUNDS; BARIUM OXIDES; CALCIUM COMPOUNDS; CALCIUM OXIDES; CHALCOGENIDES; Condensed matter: electronic structure, electrical, magnetic, and optical properties; COPPER COMPOUNDS; COPPER OXIDES; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELECTRONIC EQUIPMENT; Exact sciences and technology; HIGH-TC SUPERCONDUCTORS; LASL; MATERIALS SCIENCE; MICROWAVE AMPLIFIERS; MICROWAVE EQUIPMENT; NATIONAL ORGANIZATIONS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; Physics; Properties of type I and type II superconductors; SPUTTERING; SUPERCONDUCTING FILMS; SUPERCONDUCTIVITY; SUPERCONDUCTORS; THALLIUM COMPOUNDS; THALLIUM OXIDES; THERMODYNAMIC PROPERTIES; TRANSITION ELEMENT COMPOUNDS; TRANSITION TEMPERATURE; US AEC; US DOE; US ERDA; US ORGANIZATIONS 360202 > Ceramics, Cermets, & Refractories-- Structure & Phase Studies
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.102954

Surface resistance measurements on Tl-Ba-Ca-Cu-O thick films (∼15 μm) magnetron sputtered onto BaF2-buffered, silver-based (Consil 995) substrates have been made at a microwave frequency of 22 GHz. The relatively large-area films (∼5 cm2) are characterized by surface resistance values of 6.9±2 mΩ at 11.3 K and 30.2±1 mΩ at 77 K; the corresponding values for Cu are 10 and 22 mΩ, respectively. These results demonstrate that Tl-Ba-Ca-Cu-O can be deposited onto large-area, metallic substrates with characteristic surface resistance values lower than Cu at 4 K. Orientation of the film should improve the surface resistance at 77 K, thereby making the fabrication of microwave cavities that are superior to Cu possible.