Emission properties and site occupation of Sm3+ ion doped Lu2O3 translucent ceramics

• Lu2O3 translucent ceramics with (0.1–5 at.%) Sm were prepared by solid-state reaction.
• A detailed experimental spectroscopic investigation of Sm3+:Lu2O3 was performed.
• Sm3+ in C3i sites of Sm3+:Lu2O3 was detected by time-resolved spectroscopy.
• Extended energy levels schemes for Sm3+ C2 and C3i centers were determined.
• Lifetimes and quantum efficiencies of both Sm3+ centers emission are discussed.

High resolution spectroscopic measurements from low to room temperatures of Sm3+:Lu2O3 microcrystalline translucent ceramics, prepared by solid–state reaction method, were performed. The presence of Sm3+ in both crystallographic sites of C2 and C3i symmetry in Lu2O3 was demonstrated. Though the spectra are dominated by electric-dipole transitions of C2 centers, Sm3+ in centrosymmetric sites of C3i symmetry was detected in magnetic-dipole allowed transitions (ΔJ = 0, ±1) with significant oscillator strengths, 4G5/2 → 6H5/2, 6H7/2 in emission and 6H5/2 → 4F5/2 in excitation spectra by a quasi-selective excitation time-resolved method at 300 K. Spectral parameters such energy level schemes, concentration dependence of emission kinetics and emission quantum efficiency specific to each center are provided.