Virtual Phonon Effects in the Paramagnetic Resonance of MgO:Fe++

Abstract
A change in the g value of the spin Hamiltonian of a single ion due to virtual emission of phonons and a line broadening due to the exchange of virtual phonons between spins are considered theoretically in the system MgO: Fe++. An experimental search for these effects has proved unsuccessful because of the excessive line broadening produced by the random strain fields of the available samples.