(Keynote) Anodic Oxide Films As Electron Spectrometer

Abstract

Anodic oxide films formed by electrochemical oxidation of Al, Ti and Ta can act as spectrometer for excited electrons. The oxide films can be used as interstitial layer of so-called metal-insulator-metal systems. These systems show a device current without any applied voltage, when one of the metal’s temperature or electron distribution deviates from equilibrium. A deviation from the equilibrium for example of the top metal electrode occurs when the top metal is a catalytic metal and the device is mounted in a chemical reactor. Oxidation reactions in CO+O2 atmosphere on the catalyst surface lead to a heating of the catalyst surface and subsequently to a current from the hotter catalytic top metal to the cooler non catalytic base metal. The application of bias voltage between the non catalytic base metal and the catalytic top metal in the course of the chemical surface reaction allows a spectrometer like study of the top electrode’s state. The spectroscopic function of three different oxide films (AlOx, TiOx, TaOx) will be discussed.