Pressure and temperature-dependent Raman study ofYLiF4

Growth and characterization of LiYF4:Nd single crystal fibres for optical applications

“…The samples show similar Raman spectra, so their structural qualities are comparable. All peaks are assigned to the LiYF 4 structure symmetry [18,19]. Some peaks were not detected comparing with those identified in the literature due to the polarization lack and noise level.…”

High pressure phase transitions in scheelite structured fluoride: ErLiF4

“…1). Unlike the tungstates or molybdates [5,8,17], where the Mo-O or W-O bonds are rigid and have a covalent nature, the Li-F bond is ionic in nature [18]. These differences in the bonds character could, in principle, lead to a distinct high pressure behaviour in the fluorides vis-à-vis the tungstates and the molybdates.…”

VUV Laser Spectroscopy of Trivalent Rare-Earth Ions in Wide Band Gap Fluoride Crystals

“…Direct emission from the Stark components of the levels of the 4f n "'5d electronic configuration should be taking place only when: (1) two successive electronic levels are well separated by the combined energy of a few phonons (e.g., the phonon energy of LiYF 4 crystal is between 140 and 500 cm" 1 [152]); (2) the energy separation is larger than kT; and (3) 5d electronic configuration in the energy range from 80,000 to 60,000 cm" '. Therefore, two successive electronic levels are separated by 11 cm" 1 (assuming an even distribution of the electronic energy levels over the spectral range).…”

“…There is much interest in Ce 3+ -doped ionic crystals for applications in UV scintillators [150][151][152][153][154][155][156][157][158][159][160] and lasers [13][14][15]26]. Cerium trivalent ions in various dielectric crystal hosts are characterized by excellent photochemical stability, high conversion efficiency, and low excited-state absorption coefficient.…”