PULSED ELDOR DETECTED NMR

A pulsed EPR method for the determination of small hyperfine interacti ons in disordered systems is described. A selective preparation pulse of frequency omega(mw)(1) excites allowed and forbidden transitions, t hereby burning spectral holes into the EPR line. The positions of the holes caused by the excitation of forbidden transitions correspond to the nuclear transition frequencies of the spin system. A selective det ection pulse of frequency omega(mw)(2) creates an FID with integrated intensity proportional to the magnetization at frequency omega(mw)(2). The entire hole pattern is obtained by recording the integrated inten sity of the FID while varying the frequency difference DELTAomega(mw), = omega(mw)(1)-omega(mw)(1)-omega(mw)(2) step by step.