High pressure studies of Eu²⁺ and Mn²⁺ doped NaScSi₂O₆ clinopyroxenes

Abstract

High pressure luminescence studies of NaScSi 2 O 6 clinopyroxene (jervisite) doped with Eu 2+ and Mn 2+ arereported. The efficiency of the energy transfer between Eu 2+ and Mn 2+ is examined. It is shown that the efficiency of the energy transfer process is weakly dependent on pressure, although a small increase of the probability of nonradiative energy transfer with increase of pressure is observed. In contrast to that the energy transfer efficiency at ambient pressure is independent of temperature between 10 K and 400K. The Raman spectra under pressure shows fingerprints of the reversible phase transitions at pressures of about 100-120 kbar at room temperature.

Photoluminescence Properties of AScSi2O6:Cr3+ (A = Na and Li) Phosphors with High Efficiency and Thermal Stability for Near-Infrared Phosphor-Converted Light-Emitting Diode Light Sources

“…Sc-based silicates, such as NaScSi 2 O 6 and LiScSi 2 O 6 , have excellent physical and chemical stability and thermal stability. , There are [ScO 6 ] octahedrons in both NaScSi 2 O 6 and LiScSi 2 O 6 crystal structures. Furthermore, the radius of Cr 3+ (0.615 Å for 6-coordination) is similar to that of Sc 3+ (0.745 Å).…”

High-Pressure Near-Infrared Luminescence Studies of Fe3+-Activated LiGaO2

“…Amorphization of the nanocrystallites is reversible, although only partially since after decompression, the sample does not return to the initial crystallographic orthorhombic structure. Previously, it was observed that for Mn 2+ dopant, having the same d 5 electronic structure as Fe 3+ , in several materials (jervisite NaScSi 2 O 6 , 42 pentaborate GdZnB 5 O 10 , 41 and Tb 3 Al 5 O 12 garnet 48 ), pressure application lead to the luminescence quenching, which was associated with pressureinduced crossing between the luminescent 4 T 1g emitting level with the nonluminescent, strongly coupled to the lattice 2 T 2g level. Pressure-induced decrease in the decay time of Mn 2+ in ZnS was also observed in ZnS.…”

“…However, it seems that the distribution of the distances between the Fe 3+ ions, which act here as the energy donors, and the luminescence quenching centers, presumably on the surface of the nanocrystallites, acting as the excitation energy acceptors, is not statistical. An attempt fitting of the Fe 3+ decay kinetics with the Inokuti− Hirayama equations 42,43 does not yield fits. Therefore, we fitted the decay kinetics with the threeexponential decay curves, which give much better fits.…”

Regulating the photoluminescence and energy transfer process of Sr5(PO4)3Cl:Eu2+, Mn2+ via pressure-induced phase transition

“…Barzowska et al reported highpressure studies of Eu 2+ -and Mn 2+ -doped NaScSi 2 O 6 clinopyroxenes, and concluded that the efficiency of the energy transfer is rarely dependent on the pressure, but is remarkably suppressed in the phase transition process and then recovers under higher pressure. 34 In this work, we report the pressuredriven evolution of luminescence performance in Sr 5 (PO 4 ) 3-Cl:0.02Eu 2+ , 0.04Mn 2+ , including the change in the intensity of emission, the lifetime decay and the efficiency of the energy transfer. A phase transition has been observed at B7 GPa in the Raman spectra.…”