19F nuclear spin relaxation and spin diffusion effects in the single-ion magnet LiYF4:Ho3+

摘要: Temperature and magnetic field dependences of the 19F nuclear spin-lattice relaxation in a single crystal LiYF4 doped with holmium are described by an approach based on detailed consideration dipole-dipole interactions between nuclei impurity paramagnetic ions spin diffusion processes. The observed non-exponential long time recovery magnetization after saturation at intermediate temperatures is agreement predictions spin-diffusion theory case limited relaxation. At avoided level crossings spectrum electron-nuclear states Ho3 + ions, rates increase due to quasi-resonant energy exchange contrast predominant role played electronic cross-relaxation processes low-frequency ac-susceptibility.