Effect of Li ₂ O substitution on structures and properties of Nd ³⁺ ‐doped Al(PO ₃ ) ₃ ‐Li ₂ O glasses

Abstract 99.8[(1−x%)Al(PO ₃ ) ₃ −x%Li ₂ O]‐0.2Nd ₂ O ₃ glasses (mol%, x = 0, 5, 10, 15, 20) were prepared by high‐temperature melt and quenching method. The effect of Li ₂ O replacing Al(PO ₃ ) ₃ on the physical, mechanical, and optical properties was correlated with the network structures and the local environment around Nd ³⁺ ions, which were obtained via Raman scattering spectra, solid‐state nuclear magnetic resonance (SSNMR), and pulse electron paramagnetic resonance (EPR) techniques. SSNMR results indicate that the addition of Li ⁺ ions cannot affect the connectivity between P and Al while it can break the P‐O‐P linkages resulting in the depolymerization of glass networks. EPR spectra indicate an increasing engagement of lithium around Nd ³⁺ ions with the increase of Li ₂ O. The Judd‐Ofelt (J‐O) parameters Ω _4,6 increase, but Ω ₂ decreases. The emission cross section at 1053 nm and quantum efficiency are improved by 27% and 31%, respectively. The work is helpful for understanding the evolution mechanism of emission properties and structures in Nd ³⁺ ‐doped Al(PO ₃ ) ₃ ‐Li ₂ O phosphate glasses.