Optical materials

Excitation capture efficiency of $^5$D$_0$ europium emission level in Gd$_{0.94-x}$Eu$_x$Nb$_y$Ta$_{1-y}$O$_4$

G. A. Gusev^a, S. M. Masloboeva^b, M. V. Zamoryanskaya<sup>a

a</sup> Ioffe Institute, St. Petersburg
^b Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials Kola Science Centre of the Russian Academy of Sciences

Abstract: The article is devoted to the study of the excitation capture efficiency of Eu$^{3+}$ emission levels in Gd$_{0.94-x}$Eu$_x$Nb$_y$Ta$_{1-y}$O$_4$ ($x$ = 0.01–0.4, $y$ = 0–1) solid solutions. On the basis of the luminescence spectra analysis, it was shown that the main phase modification of the studied materials was monoclinic ($M$-polytype, $I2/a$). The quantitative describe of the excitation capture efficiency for these materials has been obtained for the first time. It was found that for all solid solutions containing Nb the excitation capture efficiency of $^5$D$_0$ Eu$^{3+}$ level was the same within the measurement error (about 2500 $\mu$m$^2$ms$^{-1}$nA$^{-1}$). In gadolinium tantalates the capture efficiency was about 15% higher. This phenomenon was associated with different excitation channels of $^5$D$_0$ Eu$^{3+}$ level in gadolinium tantalum niobates with various Nb/Ta ratio.

Keywords: gadolinium tantalum niobates, Eu$^{3+}$, cathodoluminescence, excitation capture efficiency, ceramic.

Received: 26.05.2025
Revised: 22.09.2025
Accepted: 24.09.2025

DOI: 10.61011/OS.2025.10.61954.8207-25