Chemically induced spin polarization of ion-radicals in low magnetic fields studied by double switched magnetic field CIDNP

The double switched external magnetic field CIDNP technique has been used t o study spin dynamics and chemically induced spin polarization of ion-radic als in low magnetic fields. It is shown that degenerate electron exchange l eads to decay of CIDNP oscillations. The analysis of the phase of the oscil lations provides information about electron spin polarization in low magnet ic fields. It is concluded that the exchange interaction in the radical pai rs under study is positive.