Isochemical crystallization in condensed borate LaMgB₅O₁₀ glass-ceramics doped with optical probe Eu³

The isochemical glass-ceramics doped with Eu³⁺ were prepared by the heat treatment of lanthanum magnesium borate glass. The crystalline phase was chemically identical to a glass matrix and consisted of condensed borate LaMgB₅O₁₀. The isochemical crystallization process begins with the formation of rings by BO₄ groups. The emergence of ordered crystalline phase gives rise to intense charge transfer absorption of Eu³⁺, allowing the efficient luminescence under UV. The analysis of Judd-Ofelt parameters and comparison to purely crystalline samples obtained by solid-state synthesis reveal a switch of parameter relations from Ω₂> Ω₄ for glass to Ω₂< Ω₄ for crystals but also a maximum value of Ω₆ for glass-ceramic sample, which indicates enhanced structural rigidity and results in superior luminescence output. The quantum yield measurements confirmed higher luminescence efficiency for glass-ceramics compared to both pure glass and pure crystalline samples.