Effect of Li+ co-doping on structural and luminescence properties of Mn4+ activated magnesium titanate films

• Published in: Journal of materials science. Materials in electronics Vol. 29; no. 18; pp. 15613 - 15620
• Main Authors: Borkovska, L., Khomenkova, L., Markevich, I., Osipyonok, M., Stara, T., Gudymenko, O., Kladko, V., Baran, M., Lavoryk, S., Portier, X., Kryshtab, T.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2018; Springer Nature B.V; Springer Verlag
• Subjects: Annealing; Characterization and Evaluation of Materials; Chemical Sciences; Chemistry and Materials Science; Computational Physics; Condensed Matter; Doped films; Doping; Electromagnetism; Electron paramagnetic resonance; Electron spin; Engineering Sciences; Lithium; Luminescence; Magnesium titanates; Manganese ions; Material chemistry; Materials; Materials Science; Micro and nanotechnologies; Microelectronics; Optical and Electronic Materials; Optical properties; Optics; Photoluminescence; Photonic; Physics; Reflectance; Spectroscopy; Spectrum analysis; Spin resonance; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9153-6

The effect of Li + co-doping on crystal phase formation and photoluminescence (PL) of Mn 4+ activated magnesium titanate films produced by a solid state reaction method at different temperatures (800–1200 °C) has been investigated by using X-ray diffraction (XRD), diffuse reflectance and PL spectroscopy. The chemical composition of sintered films was estimated by energy dispersive X-ray spectroscopy. The concentration of Mn impurity estimated by Electron spin resonance was about 5 × 10 16 cm −3 . The XRD study of the annealed films revealed several magnesium titanate crystal phases, such as Mg 2 TiO 4 , MgTiO 3 and MgTi 2 O 5 . The contribution of each phase depended strongly on the annealing temperature and the presence of Li + additive. Furthermore, Li + co-doping facilitated the formation of both MgTiO 3 and Mg 2 TiO 4 phases, especially at lower annealing temperatures. The PL spectra showed two bands centered at 660 and 710 nm and ascribed to the 2 E →  4 A 2 spin-forbidden transition of the Mn 4+ ion in the Mg 2 TiO 4 and MgTiO 3 , respectively. In Li co-doped films, the integrated intensity of Mn 4+ luminescence was found several times stronger compared to Li-undoped films that was ascribed mainly to flux effect of lithium.