Structural analysis of Eu3+ in Li2O-MO-B2O3-Eu2O3(M=Mg, Ca, Sr, Ba) glass using XANES and EXAFS

The research focuses on the structural changes, coordination and interatomic distance of Europium doped Li2O-MO-B2O3 (M = Mg, Sr) glasses. The detailed analysis was subjected to understand Eu3+ ions in lithium magnesium borate and lithium strontium borate glasses as determined by the extended X-ray absorption fine structure analysis. XANES spectra of Eu2O3 content doped in the present glasses showed Eu3+ state upon the x-ray as incident source. The metal LIII edges, and K edges are investigated concerning alkaline earth ion glasses and their interactions with local environment. In this work, europium and barium ions in lithium borate glasses are studied by LIII-edges, strontium and calcium ions in lithium borate glasses are studied by K-edges using X-ray absorption spectroscopy to reveal the relationship between alkali earth metal ions with Eu3+, Ba2+, Ca2+, and Sr2+ ion local structure. The nearest neighbors of Eu for the first shell were analyzed for Eu–O distance in Eu3+-doped glasses by EXAFS analysis and found to be in the range of 2.35–2.36 Å. Judd-Ofelt analyses were performed, and JO parameters showed Ω4> Ω2> Ω6 trend for Mg, Ca, Sr in lithium borate glasses while a Ω2> Ω4> Ω6 trend for Ba in lithium borate glasses. Radiative properties were analyzed using JO parameters to calculate stimulated emission cross-section, branching ratio, and radiative lifetime. The calculation was also taken care of with thermal correction and found that the data obtained after thermal correction shows higher values.