Percolation threshold model and its application to the electrical conductivity of layered BaTiO3-Ni

The electrical conductivity percolation threshold of the materials composed of conducting particles embedded in a non-conducting host matrix has been investigated. A statistical, numerical method was used, in which the particles are randomly placed, one by one, into the non-conducting host, and the conducting path is searched. The influence of different particle shapes on the percolation threshold is considered. It has been found that, in addition to the anisotropy in the dimensions of particles, the angular distribution of their long axes plays a dominant role in the calculations of the conductivity percolation threshold. Finally, the non-uniform space distribution of positions of particles is taken into account and the model is used to analyze the percolation threshold of the AC conductivity of layered BaTiO3- Ni composites.