CRYSTAL-FIELD ANALYSIS OF THE SPECTROSCOPIC CHARACTERISTICS AND MAGNETIC-PROPERTIES OF TM3+ IN LIYF4 CRYSTAL

On the basis of the analysis of a group-chain scheme and with the use of the constraint condition determined by the ratios of crystal-field parameters calculated using the point-charge model, a crystal-field-le vel fitting has been carried out for Tm3+:LiYF4, in which the Tm3+ ion s are assumed to occupy positions with point symmetry D-2d. The RMS va lue of the energy-level fitting is 11.4 cm(-1). The wavefunctions obta ined were used in the study of the magnetic, thermal, and spectroscopi c properties of the crystal. The calculated g-factors obey Karayianis' s partial g-sum rule. The temperature dependences of the Schottky spec ific heat and magnetic susceptibility agree well with data published b y others. The line shown by calculation to be the strongest is sigma-p olarized at 450.4 nm, which corresponds to blue upconversion lasing in the experiment. The method proposed turns out to be effective in the study of the spectroscopic and magnetic properties of localized centre s in crystals.