THREE CATHODES OF TANTALUM COMPOUNDS FOR FIELD-EMISSION GUNS

Tantalum tips with radius 0.1-0.5μm had been prepared by electrochemical etching, and then field-emission cathodes of tantalum nitride (Ta2N) tantalum carbide (Ta C), and tantalum carbide-nitride (TaNx Cy) with Ta-core were prepared by solidgas reaction on the surface of Ta tips. Typical field-emission patterns and work functions Regarding fild-emission characteristics were given. It is shown that tantalum compounds are promising materials for field emitters.