Article ID Journal Published Year Pages File Type
7907898 Optical Materials 2017 6 Pages PDF
Abstract
Herein, the synthesis, structural and crystal field analysis and optical spectroscopy of Mn4+ doped metal titanates ATiO3 (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 Å), and higher (Dq = 2017 cm−1) in orthorhombic CaTiO3 which possess shorter average Mn4+O2− bond distance (1.956 Å). Spectral positions of the Mn4+2Eg → 4A2g transition maxima is 709 nm in MgTiO3 and 717 nm in CaTiO3 respectively in good agreement with calculated values.
Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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