A new method for determining the relaxation times, T₁ and T₂, from progressive saturation of inhomogeneously broadened lines

An analytical method to determine the spin-lattice (T₁), and spin-spin (T₂), relaxation times for inhomogeneously broadened lines obtained from electron paramagnetic resonance (EPR) experiments is presented in this work. To apply this method, the knowledge of the lineshape of the saturation curve is not necesssary, only the Lorentzian and Gaussian widths are required and these are obtained from a non-saturated line. The relaxation times are calculated by using continuous saturation under slow passage conditions. An explicit algebraic equation for the direct calculation of T₁, and the general form of the saturation curve for a single line in an EPR signal are given. The equation given to calculate T₁ can also be used for substances in which the full saturation can not be obtained experimentally. A comparison of the results obtained for some substances by using the present method with respect to other existent ones, is carried out to show its reliability.