High pressure fluorescence studies of Sm3+-doped K-Ba-Al phosphate glass

Pressure-induced fluorescence spectra and decay curves for the 4 G 5/2 level of Sm 3+ ions in P 2 O 5 +K 2 O+BaO+Al 2 O 3 glass have been studied up to 24.4 GPa at room temperature. The study reveals that 4 G 5/2 → 6 H J (J=9/2, 7/2 and 5/2) emission band positions are shifted to lower energy (red shift) in the order of 2.4, 2.6 and 2.7 cm −1 per GPa, respectively. The increase in Stark level splittings has also been noticed with increasing pressure for the emission bands mentioned above. The decay profiles show increased non-exponential behaviour at higher pressures accompanied by a shortening of lifetimes. The non-exponential decay curves were fitted to the Inokuti-Hirayama model. The decrease in the lifetime with an increase in pressure is caused by an increase in the electronic transition probabilities. This is a result of the increased crystal-field strength around Sm 3+ ions. The original results obtained after the release of pressure confirm that no structural hysteresis takes place around the Sm 3+ ions.