GAS, LIQUID AND SOLID-STATE STUDIES OF MUON SPIN RELAXATION IN ORGANIC RADICALS

A distinctive field dependence of longitudinal muon spin relaxation in acetone liquid and vapour suggests that modulation of the isotropic hyperfine coupling of the (CH3)2COMu radical is the dominant relaxation mechanism. The temperature dependent correlation time extracted from the data then corresponds to the lifetime of the states of internal libration of the molecule. The variation of relaxation rate may also be followed into the solid phase, peaking at the freezing transition.