Аннотации:
The EPR and spin-lattice relaxation are studied of impurity rare-earth ions in LiLuF4 crystals at liquid-helium temperatures. It is detected that paramagnetic relaxation of Er3+ ions is retarded by the effect of the phonon throat. The effect of resonance attenuation of the phonon throat is clarified in two-phonon resonance relaxation processes of Er3+ ions. The Debye temperature of the crystal is determined from an analysis of experimental results. © 1988 Plenum Publishing Corporation.