A closer look at the defects and luminescence of nanocrystalline fluorides synthesized via ionic liquids: the case of Ce³⁺-doped BaF₂

Abstract

Phase pure BaF2 doped with Ce3+ (0.1%) nanocrystals are synthesized using an ionic liquid (IL) ([C4mim][BF4]) assisted solvothermal method where the IL is not only used as a reaction medium and a capping agent, but also as a reaction partner.

Yb3+ and Er3+ Codoped BaLiF3 Nanocrystals for X-ray Dosimetry and Imaging by Upconversion Luminescence

“…It is most likely that the annealing process reduces the defect density in addition to reducing the surface to volume ratio. Consequently, the ratio of surface defects to volume becomes smaller too . It appears that upon annealing, the 5% Yb 3+ sample shows higher upconversion luminescence intensity in comparison with the 10% Yb 3+ sample.…”

Multifunctional Lanthanide-Doped Binary Fluorides and Graphene Oxide Nanocomposites Via a Task-Specific Ionic Liquid

“…Commonly, the nature of diffraction peaks of particles can be related to the crystallite size and lattice strain. Therefore, the lattice strain and crystallite size can be determined by the equation of Williamson and Hall 41 where η is the effective strain, D is the crystallite size, and λ is the X-ray wavelength. When we plot β cos θ/λ versus sin θ/λ, the strain can be derived from the slope.…”

“…1% Ce 3+ -doped BaF 2 NPs are typically synthesized by a reported method. 41 Separately, 2.5 mL of aqueous solutions of barium acetate (2.8 mmol) and cerium nitrate were stirred for 5 min in separate beakers. The barium acetate and cerium nitrate solutions were mixed.…”

“… 33 , 34 However, with a judicious selection of the cation and anion combinations, physical and chemical properties of ILs can be tuned, which can influence nanomaterials synthesis. 32 , 34 − 41 The intricate properties of ILs allow them to serve as a reaction medium, capping/templating agent, and reaction partner, sometimes “all three in one”. 32 , 34 − 41 For example, ILs containing tetrafluoroborate (BF 4 – ), hexafluorophosphate (PF 6 – ), and dihydrogenphospate (H 2 PO 4 – ) anions as counterions have been used for an in situ synthesis of fluoride- and phosphate-based RE 3+ -doped nanoparticles, respectively.…”

“… 32 , 34 − 41 The intricate properties of ILs allow them to serve as a reaction medium, capping/templating agent, and reaction partner, sometimes “all three in one”. 32 , 34 − 41 For example, ILs containing tetrafluoroborate (BF 4 – ), hexafluorophosphate (PF 6 – ), and dihydrogenphospate (H 2 PO 4 – ) anions as counterions have been used for an in situ synthesis of fluoride- and phosphate-based RE 3+ -doped nanoparticles, respectively. 39 − 42 Besides this, tunable properties of ILs have been used to control the crystal phase, size, and morphology to stabilize nanoparticles, particularly metallic nanoparticles, etc.…”