Features of static and dynamic characteristics of a rhombohedric paramagnet

Static and dynamic characteristics of the rhobohedric spin S=2 paramagnet are studied theoretically for any values of the crystalline electric field, temperature, and the dc magnetic field directed along the z axis. It is shown that low-temperature static characteristics manifest ground-state crossovers, caused by the dc magnetic field. The dynamic characteristics for the case of longitudinal pumping (the ac field collinear to the dc one) are calculated in the dynamical and steady-state regimes using the solution of the master equation for the density matrix. So-called forbidden transitions with ΔSz=3 are characteristic for the longitudinal pumping of the rhombohedric paramagnet. Dynamical characteristics manifest features at two resonance frequencies, related to those transitions. Rabi-like modulations, present in the dynamical regime, disappear in the steady state one.