In pulsed EPR, spectral contributions from several species in one sample can be separated based on different EPR transition probabilities. This is usually done by monitoring the Rabi nutations in a 2D experiment. By using long pulses, the FID and echo shapes of species with different transition probabilities differ significantly, including temporal shifts of the observed echo signals in a two-pulse ESE experiment. These shifts can be used to disentangle spectral components in a 1D field-swept ESE experiment by choosing an appropriate detection time. This approach is demonstrated by experiments on a sample containing Mn(2+) and Cr(3+) centers as well as on an exchange-coupled Mn(III)/Mn(IV) system with Mn(2+) contaminations.
Copyright 2000 Academic Press.