Percolation-induced conductor-insulator transition in a system of metal spheres in a dielectric fluid.

We develop a model to investigate the insulator-conductor transition observed in a system of spherical metal particles suspended in a quasi-two-dimensional viscous liquid between planar electrodes when the voltage of the electrodes is increased. Our model captures the main ingredients of the process in experimental system, and reveals the insulator-conductor transition at a well-defined critical voltage. Based on the simulation data we demonstrate that characteristic quantities of the system show power-law scaling in the vicinity of the critical point. These scaling analysis show clearly that the transition between the insulating and conducting phases is analogous to second-order phase transitions.