Spectral And Magnetic Properties Of Impurity Tm3+ Ions In Yf3

Stark structure of H-3(6), H-3(5), H-3(4), F-3(4), F-3(3), F-3(2) and (1)G(4) multiplets of impurity non-Kramers Tm3+ ions in the orthorhombic YF3 crystal has been determined from luminescence studies. High frequency electron paramagnetic resonance (EPR) spectra (similar to 207 GHz) of Tm3+ ions have been measured at temperature 4.2 K in external magnetic field applied perpendicular to the b-axis of YF3:Tm3+ single crystal. The results of measurements are interpreted in the frameworks of the crystal field theory. The set of crystal field parameters related to the crystallographic system of coordinates of the YF3 lattice has been obtained and used to reproduce satisfactory the crystal field energies and the EPR spectra.