QUANTITATIVE-ANALYSIS OF EPR-SPECTRA OF POWDERED SAMPLES CONTAINING AMIXTURE OF VARIOUS PARAMAGNETIC PARTICLES

The prevailing majority of EPR spectra in solid samples concern the ra ndomly oriented paramagnetic particles in solids (polycrystalline samp les, powders, glasses, ceramics, frozen solutions), In these cases it is necessary to provide numerical simulation or nonlinear optimization of the spin-Hamiltonian parameters to obtain the relevant physical re sults, The presence of various paramagnetic particles in the same samp le often complicates the situation, This paper deals with the numerica l solution to these problems, Illustrative examples of EPR spectroscop y of radiation-induced paramagnetic centers in glasses and EPR of Cu(I I) as a spin label in the study of the thermal. evolution of SiO2 gel preparation are also presented. (C) 1996 Academic Press, Inc.