title: Peculiar manifestation of the dipole-dipole interaction between non-Kramers paramagnetic centers as studied by tunable high-frequency EPR spectroscopy.
abstract: EPR spectral shape of non-Kramers paramagnetic centers (PCs) is theoretically analyzed under conditions of saturation. The analysis is performed in a model that includes the spectral diffusion process induced by a random modulation of the dipole-dipole interaction of the paramagnetic centers, by reorientations of magnetic moments. It is shown that around zero magnetic field, a 'hole' might appear in the EPR spectrum. We have also studied experimentally the saturation behavior of the EPR spectrum in Cr2+: Mg2SiO4. The experimental results are interpreted in the framework of the model considered. By comparing simulated and experimental spectra, the paramagnetic relaxation times and the characteristic rate of the spectral diffusion are estimated.
authors.affiliation: Zavoisky Physical-Technical Institute of the Russian Academy of Sciences, Sibirskii Trakt 10/7, Kazan, 420029, Russia.
authors.forename: K M
authors.initials: KM
authors.lastname: Salikhov
authors.forename: V F
authors.initials: VF
authors.lastname: Tarasov