Field electron emission from large-area Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ superconducting films in vacuum

Abstract

Thin films of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-x/ deposited on copper and stainless steel electrodes by a flame spray method were tested in vacuum at electric fields ranging from 10 to 100 kV/cm. Field electron emission current was measured from the surfaces before and after the application of the film. Metallic surfaces, of 20 cm/sup 2/ in surface, cooled to LN/sub 2/ ( approximately 90 K) temperatures showed a 1.75 to 2*increase in current. The coated surfaces showed a 5 to 6* increment in current when compared to room temperature metallic surfaces. Stainless steel electrodes with a surface area of 20 cm/sup 2/, which were coated by a flame spray process and tested under vacuum, showed a similar behavior. Coating procedures and experimental results are shown. >