In LaF₃ crystals the EPR spectra of Ho³⁺ ion replacing La³⁺ ion in a C₂ symmetry position were recorded and studied in the subterahertz frequency range. The parameters of splitting in the zero field, hyperfine structure constant and the value of g-factor are determined.

Mixed-valence manganese complex oxide LiMn₂TeO₆ has dimeric, chain and planar structure motifs. Three Mn positions form an antiferromagnetic framework, and the fourth one ferromagnetically couples with it. The studies by nuclear magnetic resonance (NMR), AC and DC magnetization, specific heat methods show a non-trivial scenario of spin system transformation as temperature decrease. A change in correlation regimes with slow dynamics in high magnetic fields is found, as well as an unusual magnetic static phase at T < 6K and B < 5T. All obtained results are summarized on the magnetic phase diagram.