Luminescence of Mn4+ ions in CaTiO3 and MgTiO3 perovskites: Relationship of experimental spectroscopic data and crystal field calculations
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AuthorsĐorđević, Vesna R.
Brik, Mikhail G.
Srivastava, Alok M.
Medić, Mina M.
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Herein, the synthesis, structural and crystal field analysis and optical spectroscopy of Mn4+ doped metal titanates ATiO(3) (A = Ca, Mg) are presented. Materials of desired phase were prepared by molten salt assisted sol-gel method in the powder form. Crystallographic data of samples were obtained by refinement of X-ray diffraction measurements. From experimental excitation and emission spectra and structural data, crystal field parameters and energy levels of Mn4+ in CaTiO3 and MgTiO3 were calculated by the exchange charge model of crystal-field theory. It is found that crystalline field strength is lower (Dq = 1831 cm(-1)) in the rhombohedral Ilmenite MgTiO3 structure due to the relatively longer average Mn4+-O2- bond distance (2.059 angstrom), and higher (Dq = 2017 cm(-1)) in orthorhombic CaTiO3 which possess shorter average Mn4+-O2- bond distance (1.956 angstrom). Spectral positions of the Mn(4+2)Eg - GT (4)A(2g) transition maxima is 709 nm in MgTiO3 and 717 nm in CaTiO3 respective...ly in good agreement with calculated values. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Red luminescence / Mn4+ / Perovskite / Crystal field / LED
Source:Optical Materials, 2017, 74, 46-51
- Physics of amorphous and nanostructural materials (RS-171022)
- Cluster of excellence MATISSE [ANR-11-IDEX-0004-02], DGA (Direction Generale de LArmement, France), a [451-03-39/2016-09/19], Recruitment Program of High-end Foreign Experts [GDW20145200225], Ministry of Education and Research of Estonia [PUT430], European Regional Development Fund [TK141], g [451-03-39/2016-09/19]
- 6th International Conference of Excited States of Transition Elements (ESTE) / Workshop on Luminescence, Aug 21-26, 2016, Polanica Zdroj, Poland