Synthesis and study of the luminescent properties of terbium-activated gadolinium tantalum-niobate

For the first time, terbium-activated gadolinium tantalo-niobates were synthesized ((Gd$_{1-x}$Tb$_x$)Nb$_y$Ta$_{1-y}$O$_4$). The synthesis was carried out by the liquid-phase method. All studied materials had the main crystalline modification M GdNbO$_4$. The content of impurity phases did not exceed 2–5%. The photo- and cathodoluminescence spectra were studied. Concentration quenching of the terbium ion luminescence for a series of solid solutions containing tantalum ((Gd$_{1-x}$Tb$_x$)Nb$_{0.9}$Ta$_{0.1}$O$_4$) occurs earlier than for pure gadolinium niobates ((Gd$_{1-x}$Tb$_x$)NbO$_4$). The obtained materials are promising for use as scintillators.