Abstract
The d0 ferromagnetism in oxide films and nanoparticles without 3d elements and long-range magnetic order at concentrations of magnetic cations below the percolation limit with Curie temperature exceeding 300 K is not explained on the present understanding of magnetism in solids. It is shown that these arise in nanostructure solids when two degenerate spin-polarized macro states of the system through coupling to zero-point phonon removes the degeneracy and increases the binding energy of the system by a small amount. The coupling through quantum tunnelling persists even in the presence of thermal fluctuations until the fraction of recoilless transitions in the ground state of the lattice vanishes. This accounts for its weak intensity, universality and existence over a wide temperature range.
