Local environment of Eu3+ and Tb3+ ions in fluorophosphate glasses of the Ba(PO3)2-MgCaSrBaAl2F14 system

Abstract

The induced optical absorption and EPR absorption spectra of fluorophosphate glasses of the compositions 40Ba(PO3)2 · 60MgCaSrBaAl2F14 and 5Ba(PO3)2 · 95MgCaSrBaAl2F14 doped with Tb3+ and Eu3+ ions are investigated within the model of the effective capture volume of free carriers. The concentration dependences of the relative number of radiation centers on the dopant concentration in fluorophosphate glasses are analyzed. It is established that the character of the distribution of dopant ions in glasses depends on the dopant concentration and the structure of the glass. The critical concentrations at which the oxygen local environment of Eu3+ or Tb3+ ions in the structure of fluorophosphate glasses transforms into a mixed local environment are determined for glasses of the compositions under investigation.