Abstracts

A comprehensive evaluation of the structural and property relationships in Tb₃Al₅O₁₂:Ce³⁺ upon partial substitution of Al with Sc atoms was conducted. The inherently thermodynamically unstable Tb₃Al₅O₁₂ in the form of single crystal readily decomposed into a mixture of secondary phases [1]. However, Sc incorporation demonstrably enhanced the stability of the resulting Tb₃Al_5-xSc_xO₁₂:Ce phase, enabling its successful crystallization from the melt [2]. Systematic variation of the Sc concentration in Tb₃Al_5-xSc_xO₁₂:Ce crystals enabled the precise control of the composition and morphology of the secondary phase inclusions. At low Sc concentrations, these inclusions were primarily composed of TbAlO₃:Ce. As the Sc concentration increased, the secondary phase composition transitioned to TbScO₃:Ce. This observation suggested that Sc ions effectively replace Al ions in the secondary phase lattice, leading to a progressive compositional shift and forming garnet-perovskite sub-eutectic composition. Temperature dependence studies revealed that the rate of the energy transfer processes between Tb³⁺ and Ce³⁺ was governed by Sc³⁺ ions concentration [3]. This modulation of Sc concentration enabled the tailoring of photoconverting parameters, including correlated color temperature (CCT), color rendering index (CRI), and luminous efficacy (LE). Sc incorporation also influenced the thermal stability of Ce³⁺ ions luminescence [4]. References:[1] S. Ganschow, D. Klimm, et al., Cryst. Res. Technol. 34 (1999) 615–619. [2] O. Zapadlík, J. Pejchal, et al., J. Lumin. 263 (2023) 119984. [3] O. Zapadlík, J. Pejchal, et al., Cryst. Growth Des. 21 (2021) 7139–7149. [4] A. Markovskyi, K. Bartosiewicz, et al., Mater. Sci. Eng. B 273 (2021) 115395.