Abstract
The growth of oxide films has been observed to occur on the surface of certain metals when they are (a) subjected to an oxygen plasma, (b) subjected to an oxygen plasma and maintained at a positive potential with respect to the plasma anode, and (c) brought into intimate contact with a second metal that has oxygen dissolved in it, and maintained at a positive potential with respect to that metal. Dielectric barriers formed by these methods have been used to construct both active and passive elements in a thin film oscillator‐amplifier circuit based on the superconducting tunnel diode.