Eu-DOPED La1-xYxAlO₃: IMPACT Of Y/La RATIO ON OPTICAL PROPERTIES

Abstract

YAlO₃ and LaAlO₃ are both important oxides used as matrices in optical applications. Their mutual solid solubility is kinetically dependent, especially in a polycrystalline form. In this work, we prepared La1-xYxAlO₃ (x = 0-0.65) samples doped with 5 at% of Eu3+ in the A-site. The samples were prepared by Spark Plasma Sintering from powders synthetised by a reverse co-precipitation method. The single-phase samples were obtained up to a composition of La0.7Y0.25Eu0.05AlO₃; with a higher yttrium doping level, a mixture of Y-rich and La-rich perovskite-type phases was present. The La/Y substitution had an influence on a shift in the top of the valence band which influenced the excitation spectra. In photoluminescence and radioluminescence measurements, the Eu3+ local site symmetry changes were manifested by the change in intensity and fine splitting of the ⁵D0⟶⁷FJ (J = 1, 2, 3, 4, 5) emission bands. The increasing content of Y3+ caused a slight acceleration of the PL decay of the Eu3+ photoluminescence and an increase in the integral intensity of radioluminescence spectra.

Keywords

• perovskite
• ceramics
• optical materials
• luminescence
• spark plasma sintering