Cross-relaxation and phonon bottleneck effects on magnetization dynamics in LiYF4:Ho3+

摘要: Frequency and dc magnetic field dependences of dynamic susceptibility in diluted paramagnets $\mathrm{Li}\mathrm{Y}{\mathrm{F}}_{4}:{\mathrm{Ho}}^{3+}$ have been measured at liquid helium temperatures ac fields parallel to the symmetry axis a tetragonal crystal lattice. Experimental data are analyzed framework microscopic theory relaxation rates manifold 24 electron-nuclear sublevels lowest non-Kramers doublet first excited singlet ${\mathrm{Ho}}^{3+}$ ground multiplet $^{5}I_{8}$ split by ${S}_{4}$ symmetry. The one-phonon transition probabilities were computed using electron-phonon coupling constants calculated exchange charge model checked optical piezospectroscopic measurements. specific features observed in- out-of-phase susceptibilities (humps dips, respectively) crossings (anticrossings) well reproduced simulations when phonon bottleneck effect cross-spin taken into account.