THE EFFECT OF LATTICE STRAINS ON THE ACOUSTIC RELAXATION LOSSES IN DIELECTRIC CRYSTALS DUE TO MAGNETIC IONS

Abstract
Recently information on the lattice strains present at Fe²⁺ sites in KMgF₃ has been obtained from electron spin resonance linewidth data. The use of this data in an empirical model previously used with success on Fe²⁺ : MgO shows that this model also gives an excellent description of the acoustic relaxation losses in Fe²⁺ : KMgF₃. In order to place this empirical model on a more sound theoretical footing a theory of relaxation losses in multi-level systems based on the rate equations for the population of each level has been studied. The empirical model results only if simplifying assumptions are made and the implications of these are described.