High-Pressure Effect in Vis–NIR Emission of Sm³⁺-Doped GeO₂–PbO Glasses

Abstract

Spectroscopic and structural properties of GeO2–PbO glasses doped with Sm3+ ion were investigated before and after densification at 7.7 GPa using X-ray difraction, Raman spectroscopy, ellypsometry, Extended X-ray absorption fine structure (EXAFS) and absorption and luminescence spectroscopy. Judd–Ofelt (J–O) intensity parameters Ωλ (λ = 2, 4, and 6) were calculated and the Ω2 parameter decreased for the glass after densification at 7.7 GPa due to the structural changes of the host glass induced by pressure. Shifts in the Raman band toward lower energies and variations in the intensities of the EXAFS curves indicated that the local environment around Sm3+ became more symmetric after densification, with shorter average Sm–O distances than in the crystalline standard. The radiative properties in the vis and NIR regions were also affected by high pressure.