HYPERFINE-CORRELATED ELECTRON-NUCLEAR DOUBLE-RESONANCE SPECTROSCOPY

A pulse electron nuclear double resonance method is proposed that corr elates the hyperfine splittings to the nuclear transition frequencies in a two-dimensional experiment. Since the technique makes use of sele ctive radio frequency excitation in a time-domain experiment it can be applied to ordered systems as well as to disordered systems with hype rfine inhomogeneities and no or only small nuclear quadrupole inhomoge neities. The intensity of artifact peaks is found to depend on the pha se of the radio frequency field which in turn is defined with respect to the geometry of the spin system. The theoretical predictions are co nfirmed by experiments on a single crystal and on a spin-label-doped p olymer.