Sol-gel Processing and Characterization of Alkaline Earth and Rare-earth Fluoride Thin Films

Abstract

Alkaline earth and rare-earth fluoride thin films were prepared on silica glass substrates by a sol-gel process using trifluoroacetic acid (TFA) as a fluorine source. Homogeneous solutions were obtained by stirring a mixture of alkaline earth or rare-earth metal acetates, TFA and H2O, dissolved in isopropanol. The solutions were spin-coated and heated at 300–800 °C. The fluoride thin films were obtained by heat treatment around 400 °C in air. The crystallization behavior, the surface morphology, and the optical properties of the films depended on the heating temperature as well as the chemical species of the metal ions.

Luminescence studies of the rare earth ions-doped CaF2 and MgF2 films for wavelength conversion

“…3. It was found that the oxidation of the alkaline earth and rare earth fluorides took place at high temperature of 600 • C by XRD measurements [7].…”

“…These differences are presumably due to the formation process of alkaline earth fluorides in sol-gel synthesis. It was studied that the decomposition of the alkaline earth and lanthanide trifluoroacetate gels by heating obeys following reactions [6][7][8]:…”

“…The optical characterization and sol-gel synthesis of porous alkaline earth and lanthanide fluoride films using the hydrofluoric acid (HF) [5] and the trifluoroacetic acid (TFA, CF 3 COOH) [6][7][8][9] have been studied. In the present study, the Eu and Yb ions-doped CaF 2 and MgF 2 films as the UV to visible conversion layer were prepared by the vacuum deposition and the sol-gel methods.…”

Reduction of Eu2+-activated nanoparticles by unique TCRA treatment

“…A number of researches have been reported to focus on the synthetic methods and characterizations of rare earth fluoride and rare earth doped alkaline-earth fluoride using the HF [1], trifluoro-acetates [2][3][4][5] and 1,1,1-trifluoro-5-methyl-2,4-hexanedione [6]. Above all, the luminescent [7,8], scintillation properties [9,10] and applications to the solar cell [11] have been studied for Eu doped CaF 2 single crystal.…”

Effect of pressure on structural, electronic and optical properties of SrF2: a first principles study

“…Their structural, optical, lattice dymamic and elastic properties have been extensively studied [1][2][3][4][5][6]. Due to their unique properties, including low energy phonons, optical transparency, high resistivity and anionic conductivity [7], SrF 2 has been applied in scintillation detectors [8] and luminiscent materials [9,10].…”