Self-Organized Networks and Lattice Effects in High Temperature   Superconductors
  The entirely orbital self-organized dopant percolative filamentary model describes many counter-intuitive chemical trends in oxide superconductors quantitatively, especially the high superconductive transition temperatures Tc. According to rules previously used successfully for network glasees, the host networks are marginally stable mechanically, and the high Tc's are caused by network softening, which produces large electron-phonon interactions at interlayer dopants for states near the Fermi energy. 
J. C. Phillips