Nanosystem atomic structure stability during the molecular switching

In the article the mathematical model of the phase transition from high-resistance amorphous state to low-resistance crystalline state is developed. The study is made, employing quantum molecular dynamics. The semiconductor structure is analyzed and changes of conductivity and heat capacity during the phase transition are estimated. Found process is simulated by the model of a continuous medium with Joule heating source. Stability of the nonlinear heat conduction problem solutions is studied, when the current-voltage characteristics are in the region of negative differential conductivity. The phase-change memory performance, associated with the molecular system instability, is discussed.