Effect of B2O3 content on Eu3+−Surrounding in the system SrO−x.B2O3 containing Eu3+ ions prepared by combustion method

Highlights: • The SrO-x.B₂O₃ (x = 0.33, 0.5, 1) materials were synthesized by combustion method at 600 °C. • When B₂O₃ content increases from 25 to 50 mol% the electronphonon coupling strength is increasing. • The existence of an incremental asymmetry in local environment around Eu³⁺ ions is a result of the adding B₂O₃ content. -- Abstract: The change of Eu³⁺− surrounding in the system SrO−x.B₂O₃ with various x values (x = 0.33, 0.5, 1) synthesized by combustion method was investigated via photoluminescence (PL) spectra and phonon sideband (PSB) spectra. From the analysis of PSB spectra, it is reasonable to suggest that when increasing B₂O₃ content the electron−phonon coupling strength increases due to the increase in the number of BO⁻ non−bridging bond. By using Judd−Ofelt (JO) theory for PL spectra of Eu³⁺ ion, the Ω₂ intensity parameter was calculated and it also shows the asymmetry of Eu³⁺− surrounding increase corresponding to the B₂O₃ content.