Energy transport in photoexcited crystals of ${\mathrm{K}}_3$[Tb(${\mathrm{C}}_2$${\mathrm{O}}_4$${)}_3$(${\mathrm{H}}_2$O)]⋅${2\mathrm{H}}_2$O: Transfer from ${\mathrm{Tb}}^{3+}$ to ${\mathrm{Nd}}^{3+}$ and ${\mathrm{Eu}}^{3+}$

The luminescence decay dynamics of ${\mathrm{Tb}}^{3+}$ ${(}^5$ ${\mathit{D}}_4$) and Eu${(}^5$ ${\mathit{D}}_0$) in triclinic (P1¯) crystalline ${\mathrm{K}}_3$[Ln(${\mathrm{C}}_2$ ${\mathrm{O}}_4$ ${)}_3$(${\mathrm{H}}_2$O)]⋅${2\mathrm{H}}_2$O solids was studied between 10 and 298 K in order to establish the energy-transport characteristics. The luminescence decay rate of ${\mathrm{Tb}}^{3+}$ (740 ${\mathrm{s}}^{\mathrm{-}1}$ for Ln=${\mathrm{Tb}}^{3+}$) is temperature independent for the pure terbium complex; with introduction of ${\mathrm{Ln}}^{3+}$ dopants (e.g., Ln=Nd, Eu) faster decay rates which are temperature dependent are obtained. For the ${\mathrm{Eu}}^{3+}$ dopant, excitation buildup on the ${\mathrm{Eu}}^{3+}$ ${(}^5$ ${\mathit{D}}_0$) decay curve upon ${\mathrm{Tb}}^{3+}$ ${(}^5$ ${\mathit{D}}_4$) excitation confirms that energy transfer from ${\mathrm{Tb}}^{3+}$ ${(}^5$ ${\mathit{D}}_4$) to ${\mathrm{Ln}}^{3+}$ is active. The temperature dependence of the energy-transfer process in the ${\mathrm{K}}_3$[${\mathrm{Eu}}_{0.83}$ ${\mathrm{Tb}}_{0.17}$(${\mathrm{C}}_2$ ${\mathrm{O}}_4$ ${)}_3$(