NUCLEAR-SPIN RELAXATION OF PR3- A TEMPERATURE-DEPENDENT OPTICAL-RF DOUBLE-RESONANCE STUDY( IN YALO3 )

The decay rates of the nuclear spin polarization of Pr3+ in a YAlO3 ma trix were measured in the temperature range 3-9 K by time-resolved spe ctral hole burning and simultaneous radio-frequency irradiation. In th e low-temperature limit, diffusion of spin polarization to other regio ns of the inhomogeneously broadened optical resonance line dominates t he relaxation. At higher temperature, thermally activated multiple pho non processes become dominant.