Dielectric properties of Al-Nb amorphous mixed oxides

摘要

An impedance study of amorphous thin oxide films grown on sputtered Al-Nb alloys is presented. The characterization of the electronic properties of mixed amorphous oxide on the basis of the theory of amorphous semiconductor Schottky barrier has been carried out for anodic film on Al-92at.%Nb in a very detailed manner. The semiconductor to insulator transition of formed oxides as a function of the alloy composition at fixed final voltage has been supported by differential admittance study. A possible rationale for this transition has been suggested taking into account the changes of solid state properties, optical bandgap and electronic structure of the films, derived from the fitting of the differential admittance curves at different frequencies.