Self-organized percolation model of high-temperature superconductivity in ferromagnetic cuprates and tungsten bronzes

The recently discovered superconductivity in the titled materials, at 45K and 90K, respectively, is almost as surprising phenomenologically as high-temperature superconductivity (HTSC) itself. Nevertheless, the microscopic theory of filamentary intermediate phases, recently developed for semiconductor impurity bands and layered HTSC cuprates, and even for network glasses, explains the existence of these phenomena with no new assumptions. The ultimate mechanism responsible for filamentary formation is self-organization, which minimizes the dopant-related free energy at the formation temperature.