Elaboration, Structure, and Luminescence of Eu³⁺‐Doped BaLuF₅‐Based Transparent Glass‐Ceramics

Abstract

Novel Eu3+‐doped transparent oxyfluoride glass‐ceramics containing BaLuF5 nanocrystals were successfully fabricated by melt‐quenching technique for the first time. Analyses of XRD patterns prove that the new precipitated glass‐ceramics are crystallized in cubic BaLuF5 based on isostructural BaGdF5. Intense red emissions observed in glass ceramics are attributed to the enrichment of Eu3+ ions into BaLuF5 nanocrystals. Besides, obvious stark splitting emissions, low forced electric dipole 5D0→7F2 transition, and long decay lifetimes of Eu3+ ions also evidence the partition of Eu3+ ions into BaLuF5 nanocrystals with low phonon energy. Such transparent material may find applications in photonics.

A new parameter for characterizing Eu3+ distribution in mixed‐valence Eu‐doped cubic LaF3‐based transparent glass‐ceramics

“…There are two sets of excitation signals appearing in excitation spectra: one broadband at 281 nm originating from O 2− -Eu 3+ charge transfer (CT) band and several characteristic sharp peaks assigned to 4f-4f transitions of Eu 3+ ions (300-550 nm). 23,31 However, in the case of our LaF 3 -based glass-ceramics, the intensities of CT bands increase after crystallization, which suggests that Eu 3+ ions still remain in the glass phase after crystallization. Excited by 393 nm, the electrons of Eu 3+ at ground 7 F 0 state can be pumped onto high-energy 5 L 6 excited state.…”

“…Eu 3+ -related excitation (λ em = 613 nm) and emission (λ ex = 393 nm) spectra of PG and GC samples are given in Figure 5A,B, respectively. 23,31 In those glass-ceramics, Eu 3+ ions were homogeneously dispersed in the oxide glass phase and the O 2− -Eu 3+ bond was strongly coupled, leading to the prominent CT band in precursor glass. 23,31-34 The strongest excitation peak at 393 nm in Figure 5A corresponds to 7 F 0 → 5 L 6 transition of Eu 3+ .…”

Upconversion luminescence in BaYF5, BaGdF5 and BaLuF5 nanocrystals doped with Yb3+/Ho3+, Yb3+/Er3+ or Yb3+/Tm3+ ions

“…The crystal phases of the theoretical compositions of BaREF 5 have been obtained by many researchers [2,20,22,23,[53][54][55][56][57][58][59][64][65][66][67][68][69][70][71][72][73][74][75][76][77]. The first reports about BaYF 5 and BaLuF 5 date back to 1969, [78] and that on BaGdF 5 to 1988 [79].…”

“…BaYF 5 and BaGdF 5 have been proved to be suitable hosts for upconversion nanophosphors, doped with lanthanide ion pairs mentioned before. However, there have been only a few works concerned with other BaREF 5 phosphors, such as BaLuF 5 [50][51][52][53][54][55][56][57][58][59]. In particular, the spectroscopic properties of materials based on these hosts have not been compared as yet.…”

Luminescent properties of Eu3+-doped glass ceramics containing BaGdF5 nanocrystals under NUV-excitation for W-LEDs

“…Nanocrystals and glass phase were distributed homogeneously in glass ceramics by glass annealing. Glass ceramics can keep high transparency by controlling the size and phase of microcrystal, which have been a hot matrix materials rare ions doped [9][10][11][12][13]. Rare earth doped BaYF 5 and BaLuF 5 3 both have been reported [14 15].…”