Optical, scintillation and luminescent properties of 0.1% Ti-, Mn- and Cu- doped lithium aluminate LiAlO2 crystals are studied. The crystals were grown by micro-pulling down (μ-PD) method under N2 + O2 (2 vol %) atmosphere. By the X-ray excitation, the crystals exhibited intense emission bands at ultraviolet-visible regions which can be attributed to the Ti4+-O2- charge transfer transition at 380 nm, 4T1 → 6A1 transition of Mn2+ ion at 550 nm and 3d94s-3d10 transition of Cu+ at 360 nm, respectively. The scintillation decay time were estimated to be about 1.8 and 9.9 μs for Ti 0.1%, 310 μs and 2240 μs for Mn 0.1%, and 3.6 μs and 19.6 μs for Cu 0.1%. When 252Cf neutron irradiated the crystals, the relative scintillation light output found to be approximately (135 ± 13) × 102 ph/n (for Ti 0.1%) and (87 ± 8.0) × 102 ph/n (for Cu 0.1%) compared to that of GS20 commercial scintillator. Both TL and OSL spectra showed emission bands caused by the recombines of trapped electrons at the anion centers through the Ti4+, Mn2+ and Cu+ luminescence centers. The irradiation dose response was linear in the studied dose range at 0.1-5 Gy and 0.1-10 Gy.
- Lithium aluminate
- Optically stimulated luminescence
- Transition metals
ASJC Scopus subject areas