Photostimulated creation of electron and hole centers in YAlO3:Mn: Thermoluminescence and electron paramagnetic resonance study

Photostimulated creation of electron and hole centers in YAlO3:Mn: Thermoluminescence and electron paramagnetic resonance study

WoS Article

X-ray synchrotron diffraction, photoluminescence (PL), and thermally stimulated luminescence (TSL) were employed to investigate manganese-doped YAlO3 single crystals and microcrystalline powders over the temperature range of 90-680 K. Anomalous thermal quenching of the Mn4+-related photoluminescence was observed. The photostimulated formation of electron and hole centers was studied under selective irradiation at various temperatures (295-610 K) within the Mn4+ absorption range (2.3-5.8 eV). Excitation spectra of TSL glow curve peaks, activation energies of their creation by photons of different energies, and dependencies of TSL glow curve peak intensity on the irradiation duration were analyzed. Based on PL and TSL data, possible charge-transfer mechanisms are proposed and the positions of Mn4+ energy levels within the YAlO3 band gap are suggested. The valence states of Mn ions are clarified by measurements of electron paramagnetic resonance (EPR) spectra at a wide range of microwave frequencies (9.4, 34, and 150 GHz) and at temperatures down to 5 K. In non-irradiated YAlO3:Mn crystal, only the EPR spectra of Mn2+ and Mn4+ ions are detected. Ultraviolet irradiation in the 3.4-4.7 eV energy range leads to partial recharging of Mn4+ (3d(3), S = 3/2) and Mn2+ (3d(5), S = 5/2) ions to the valence states with even spin numbers, which means that these ions trap or lose one electron. Combining PL, TSL, and EPR data, the formation of Mn5+ and Mn1+ ions under ultraviolet irradiation is confirmed.

X-ray synchrotron diffraction, photoluminescence (PL), and thermally stimulated luminescence (TSL) were employed to investigate manganese-doped YAlO3 single crystals and microcrystalline powders over the temperature range of 90-680 K. Anomalous thermal quenching of the Mn4+-related photoluminescence was observed. The photostimulated formation of electron and hole centers was studied under selective irradiation at various temperatures (295-610 K) within the Mn4+ absorption range (2.3-5.8 eV). Excitation spectra of TSL glow curve peaks, activation energies of their creation by photons of different energies, and dependencies of TSL glow curve peak intensity on the irradiation duration were analyzed. Based on PL and TSL data, possible charge-transfer mechanisms are proposed and the positions of Mn4+ energy levels within the YAlO3 band gap are suggested. The valence states of Mn ions are clarified by measurements of electron paramagnetic resonance (EPR) spectra at a wide range of microwave frequencies (9.4, 34, and 150 GHz) and at temperatures down to 5 K. In non-irradiated YAlO3:Mn crystal, only the EPR spectra of Mn2+ and Mn4+ ions are detected. Ultraviolet irradiation in the 3.4-4.7 eV energy range leads to partial recharging of Mn4+ (3d(3), S = 3/2) and Mn2+ (3d(5), S = 5/2) ions to the valence states with even spin numbers, which means that these ions trap or lose one electron. Combining PL, TSL, and EPR data, the formation of Mn5+ and Mn1+ ions under ultraviolet irradiation is confirmed.

XRD; photoluminescence; anomalous thermal quenching; Thermoluminescence; EPR; YAlO3:Mn

XRD; photoluminescence; anomalous thermal quenching; Thermoluminescence; EPR; YAlO3:Mn

Krasnikov, A.; Laguta, O.; Laguta, VV.; Vasylechko, L.; Zazubovich, S.

01.10.2025

ELSEVIER

AMSTERDAM

1873-1252

OPTICAL MATERIALS

167

117272

Kingdom of the Netherlands

15

https://www.sciencedirect.com/science/article/pii/S0925346725006329?via%3Dihub