Initial stage of nanometer metal films electrical explosion: Current action integral and electrothermal instability

Abstract

An electrical explosion of nanometer (∼20 nm) metal films onto polymer substrate at the current densities of ∼1012A/m2 is studied theoretically. The initial stage of explosion is considered with respect to current action integral and development of electrothermal instability. It is revealed that the effective value of specific action integral is larger than its value for the vacuum conditions due to the heat outflow into the substrate. The paper considers a linear perturbation analysis of thermal state in order to find the marginal condition for electrothermal instability. This instability leads to the formation of strata structures arranged normally to the direction of current flow before the melting stage.