Structural and luminescence properties of Sm3+ ions in zinc fluorophosphate glasses

• Sm3+-doped zinc fluorophosphate (ZFPSm) glasses have been prepared and analyzed.
• Thermal, Raman and spectroscopic properties have been carried out.
• ZFPSm glasses exhibit intense reddish-orange emission under 401 nm excitation.
• Non-exponential decay rates revealed the presence of dipole–dipole interactions.
• ZFPSm glasses are found to be suitable for reddish orange visible lasers.

Sm3+-doped zinc fluorophosphate (PKAZLFSm) glasses have been prepared by conventional melt quenching technique and are characterized through thermal, Raman, absorption, emission and decay rate analysis. The Judd–Ofelt (JO) theory has been used to derive the spectroscopic properties of Sm3+:PKAZLFSm glasses. The decay rates for the 4G5/2 level of Sm3+ ions have been measured and are found to be single exponential at lower concentration (⩽0.1 mol% Sm2O3) and turns into non-exponential at higher concentrations (⩾0.5 mol% Sm2O3) due to energy transfer through cross-relaxation. The experimental lifetimes for 4G5/2 level of Sm3+ ions are found to decrease from 3.2 to 0.5 ms when the concentration increased from 0.01 to 4.0 mol% Sm2O3 due to energy transfer among Sm3+ ions. In order to know the nature of the energy transfer mechanism, the non-exponential decay rates are well fitted to Inokuti–Hirayama model for S = 6, indicating that the energy transfer process is of dipole–dipole type. The results obtained for the 4G5/2 → 6H7/2 transition indicate that the Sm3+:PKAZLFSm10 glass can be very much useful for the development of visible lasers in the reddish orange spectral region.