Percolation mechanism for colossal magnetoresistance

We propose a new mechanism to explain colossal magnetoresistance. The explanation assumes that the materials displaying colossal magnetoresistance are halfmetallic and proposes that the effect is a critical phenomenon, which is intimately connected with the ferromagnetic-to-paramagnetic phase transition present in these materials. The proposed mechanism is a percolation mechanism; the behavior of the resistance is described using a resistor network. An analysis of the percolation phase diagram and Monte Carlo calculations on the resistor network show a full qualitative correspondence with the experimentally observed features of colossal magnetoresistance. Copyright (C) 1998 Elsevier Science B.V.