VUV spectroscopy of pure and Tm3+-doped LicaAlF6 crystals

Vacuum ultraviolet excitation spectra of lanthanide-doped hexafluoroelpasolites

“…The value is fairly close to that reported for LiCaAlF 6 :Eu 3+ [76]. The E CT (expt) value for Tm 3+ is the value for this ion in the host LiCaAlF 6 [108] (given in [77]) and is expected to be a reasonable approximation (with errors up to a few thousand of cm −1 ) judging from the small variation of F − -Eu 3+ CT band energies in various hosts [109]. The data in round parentheses in table 2 for the ions from Tb 3+ to Yb 3+ represent the energies of the onset of spin-forbidden 4f N -4f N −1 5d absorption.…”

“…There are two exceptions. First, the VUV excitation spectra of Tm 3+ in the LiMAlF 6 (M = Ca, Sr) hosts [77,78], and the VUV absorption spectrum of Nd 3+ in LiCaAlF 6 [75], have been reported. In this host, the Ln 3+ ions are situated at the Ca 2+ D 3d site in a trigonally elongated octahedral coordination.…”

“…However, as also for the 4f 3 → 4f 2 5d spectrum of Nd 3+ , all of the bands are situated at higher energies in the LiCaAlF 6 host than in the elpasolite. True et al [77] have remarked that the peak energy of the first fd band depends on the crystal field splitting, increasing with increasing Ln-F bond distance. In fact, the Ca-F distance (229 pm) [111] in the LiCaAlF 6 host is a little longer than the Y-F distance (227 pm) in Cs 2 NaYF 6 .…”

UV–VUV-excited photoluminescence of Tm3+ substituted β-rhenanite as a blue-emitting phosphor

“…With an expectation of engendering a new blue phosphor, many researchers have concentrated their attention on Tm 3 + substituted host as Tm 3 + could offer blue emission in various systems [5][6][7][8]. They considered the simplicity of the 4f level structure of Tm 3 + beneficial for applications, owing to the prohibition of energy dissipation between many different relaxation channels, whereas most rare-earth (RE) ions have significantly more 4f levels [9].…”

Blue luminescence of nanocrystalline CaZrO3:Tm phosphors synthesized by a modified Pechini sol–gel method

“…For example, BAM:Eu significantly loses the radiation efficiency, and simultaneously accompanies a color shift during the thermal treatment at the temperature of 450-550 1C [5,6]. With a motivation to develop a new blue phosphor, many investigations have been done on Tm 3+ -activated oxides, because Tm 3+ can provide blue luminescence and can be doped at a high concentration [7][8][9][10][11]. As to the host, the preferential selection is A 2+ B 4+ O 3 oxides with the perovskite-type structure, because they are sufficiently conductive to release electric charges stored on the phosphor particle surfaces, which results in their potential applications in solid oxide fuel cells, hydrogen sensors, in field emission display (FED) and PDP [12].…”