Energy transfer in crystals $\mathrm{LiY_{0.3}Lu_{0.7}F_4:Ce}^{3+}$, $\mathrm{Pr}^{3+}$

The paper presents the results of an investigation of the excitation energy transfer from $\mathrm{Pr}^{3+}$ ions to $\mathrm{Ce}^{3+}$ ions. The absolute concentrations of $\mathrm{Ce}^{3+}$ and $\mathrm{Pr}^{3+}$ ions in crystals $\mathrm{LiY_{0.3}Lu_{0.7}F_4:Ce}^{3+}$, $\mathrm{Pr}^{3+}$ are determined, and the coefficient of the excitation energy transfer from $\mathrm{Pr}^{3+}$ ions to $\mathrm{Ce}^{3+}$ ions is estimated.