Pressure dependent luminescence properties of Sm3+ ions in fluorophosphate glass

Pressure dependent luminescence spectra and decay curves for the 4G5/2 level of Sm3+ ions in fluorophosphate glass of composition 55.975 P2O5 + 14 K2O + 6 KF + 14.975 BaO + 9 Al2O3 + 0.05 Sm2O3 (referred as PKFBASm005) have been measured as a function of pressure up to 40.2 GPa. In this pressure range, the red-shift (during increase in pressure), the blue-shift (while releasing pressure) and enhanced crystal-field splitting with increase in pressure are observed for 4G5/2 → 6HJ (J = 9/2,7/2 and 5/2) multiplet transitions of PKFBASm005 glass. These pressure induced shifts as well as crystal-field splittings were explained by the interaction of Sm3+ ions with its surrounding ligands under pressure. The decay curves for the 4G5/2 level are found to be non-exponential in the entire pressure range. The lifetime for the 4G5/2 level decreases from 3.23 to 1.62 ms with increase in pressure from ambient to 40.2 GPa. The generalized Yokota-Tanimoto (YT) model has been used to explain non-exponential behaviour of decay curves.