Localization effects in nuclear spin relaxation of a charge-transfer complex

The measurement of nuclear spin lattice relaxation rate has been performed on charge-transfer (CT) complexes based on the donor molecule of bisethylenedioxytetrathiafulvalene (BO). The relaxation rate of a CT complex of BO and decyltetra cyanoquinodimethane (C10TCNQ) exhibits a noticeable peak at low temperatures. The behaviors of the peak are characterized by Anderson localization in weakly disordered systems. Through the quantitative analyses of the peak, the detailed dynamics of the localized electrons of the system has been provided successfully.