Site symmetry dependence on luminescence emission of Y₂O₃:Eu³⁺ dispersed in silica matrix

ABSTRACT

Lanthanide ion (Ln³⁺) doped Y₂O₃ materials are used in making display devices. Ln³⁺ ions can occupy C₂ and S₆ sites in Y₂O₃. In many reported papers, Ln³⁺ ions occupy more C₂ site leading to enhanced luminescence intensity of electric dipole transition as compared to that of magnetic dipole transition. In this study, we have prepared Eu³⁺ ion doped Y₂O₃ particles dispersed in silica (SiO₂) using urea hydrolysis at 165°C. Among the prepared samples lower heated sample show cubic phase Y₂O₃ wherease 1400^oC show α-Y₂Si₂O₇ and all the samples show the luminescence characteristics of Eu³⁺. In Y₂O₃:Eu-SiO₂, the as-prepared, 500 and 900°C heated samples show the higher luminescence intensity for the electric dipole transition than that of magnetic dipole transition and it is opposite upon annealed at 1400°C. It confirms that Eu³⁺ ions in as-prepared, 500 and 900°C heated samples occupy C₂ site (asymmetric environment), whereas in 1400°C heated sample, they occupy the S₆ site (symmetric environment). However, microparticles of the Y₂O₃:Eu sample annealed at 1400°C show that Eu³⁺ ions occupy more C₂ site as compared to the S₆ site. This study suggests that occupancy of C₂ and S₆ sites in Y₂O₃ by Eu³⁺ ions can be varied by surrounding medium as well as heat-treatment temperature.

KEYWORDS:

• Nanoparticle
• emission
• excitation
• dispersion
• asymmetric ratio

Acknowledgments

The author thanks Dr. R.S. Ningthoujam, Chemistry Division, BARC Mumbai, for his kind cooperation and suggestions while preparing this manuscript.

Disclosure statement

There is no conflict of interest in this artilcle.

Supplementary material

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