Details

Autor(en) / Beteiligte

• Przybylińska, Hanka
• Zhydachevskyy, Yaroslav
• Grochot, Aneta
• Wołoś, Agnieszka
• Stasiv, Vasyl
• Glowacki, Michał
• Kaminska, Agata
• Ubizskii, Sergii
• Berkowski, Marek
• Suchocki, Andrzej

Titel

Electron Paramagnetic Resonance and Optical Studies of Thermoluminescence Processes in Mn-Doped YAlO3 Single Crystals

Ist Teil von

• Journal of physical chemistry. C, 2022-01, Vol.126 (1), p.743-753

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A detailed electron paramagnetic resonance (EPR), optical absorption, luminescence, and thermoluminescence (TL) study of Mn-doped YAlO3 (YAP) single crystals was performed. The crystals were grown by the Czochralski method from stoichiometric (Y/Al = 1) and yttrium-rich (Y/Al = 1.04) melts and codoped with either Si or Hf ions. The EPR measurements revealed the presence of only one type of Mn2+ center, that is, isolated Mn ions occupying Y sites (MnY 2+). It was found that only in yttrium-rich crystals, the MnY 2+ ions undergo recharging to MnY 3+ under ionizing irradiation, indicating that this process requires the availability of sufficiently deep electron traps. The initial charge state is fully restored only after subsequent warming above 600 K. The presented results demonstrate, moreover, that MnY 3+ + e → MnY 2+ recombination is not the most efficient excitation channel of the green 4T1 → 6A1 emission of MnY 2+, possibly because of the huge energy difference between the recombination (>5.39 eV) and excitation (3 eV) energies. In contrast, energy transfer to MnY 2+ proves to be dominant. A general model of trapping and recombination mechanisms responsible for TL of YAP:Mn crystals above room temperature is proposed. Besides MnY 2+ ions and the defect-related electron and hole traps intrinsic to the YAP lattice, the model includes also unintentional dopants such as FeAl 2+ acting as deep hole traps, as well as MnAl 4+ and CrAl 3+ ions acting both as deep hole and electron traps.