Mechanical and electrical characteristics of silver stabilizer layer prepared by using nano silver paste for coated conductor

Abstract

Mechanical and electrical properties of silver stabilizer layer of coated conductor, which was prepared using nano silver paste as starting materials, have been investigated. Nano silver paste was coated on YBCO (Y 1Ba 2Cu 3O 7− δ ) film by a dip coating method with a speed of 25 mm/min. Coated film was dried in air and heat treated at 400–700 °C in a flowing oxygen atmosphere. Adhesion strength between YBCO and silver layer was measured by Tape test (ASTM D 3359). The hardness and electrical conductivity of the sample were measured by pencil hardness test (ASTM D 3363). Surface and volume resistance were measured by using LORESTA-GP (MITSUBISHI). The sample heat treated at 500 °C showed poor adhesiveness of 1B but it is clearly enhanced to 5B when samples were heat treated at higher than 600 °C. The silver layer heat treated at 700 °C showed a high hardness value of higher than 9H and a volume resistance of 1.417 × 10 −7 Ω mm at room temperature. SEM observations showed that a dense silver layer was formed with a thickness of about 2 μm. Dip coated silver layer prepared by using nano silver paste showed superior electrical and mechanical characteristics which is comparable to those that sputter deposited Ag layer.