Thermal instability—The precursor to switching in inhomogeneous thin films

Thermal stability criteria capable of explaining Thoma´s observations that bias-induced reversible switching transitions in inhomogeneous thin insulating and semiconducting films occur at a critical value of local power density are developed and analyzed. One model, based on a relation between the temperature and heat current, is then applied to specific inhomogeneous thin amorphous chalcogenide films, and good qualitative agreement is shown to exist between theory and experiment.