The mechanism of origination of anomalous features in the structure of short-wavelength spectra of fluoride matrices doped with rare-earth ions

A comparative study of the optical and structural parameters was performed for $BaY_2F_8$ and $KY_3F_{10}$ single crystals doped with $Er^{3+}$, $Но^{3+}$, $Yb^{2+,3+}$, and $Тm^{2+,3+}$ ions. An interrelation was established between the occurrence of regular structure imperfections in single crystals and the anomalies in their VUV spectra, which may be utilized to improve the luminescence parameters of the materials studied.