Luminescence characterization of Mn-doped LiMgPO4 synthesized using different precursors

Abstract

In the present study, precipitation method was used to synthesize three Mn-doped minerals, namely, dittmarite, struvite, and newberyite, and LiMg0.74Mn0.26PO4 phosphor was prepared through thermal synthesis using each of the afore-mentioned minerals as a precursor. Slight changes in the X-ray diffraction positions in the Mn-dopants validated that the pure-doped phase resulted in the changes in cell volumes and lattice parameters, which demonstrated that the Mn-dopants retained the undoped crystal structures. Photoluminescence (PL) of the phosphors derived from different precursors was examined under various conditions, in terms of physical and luminescent properties. The observed PL was dependent on the surface area, synthesis temperature, particle size, and crystallite size. The energy gap (Eg) value for LiMg0.74Mn0.26PO4 synthesized at 900 ​°C was also determined (5.492 ​eV), and was observed to be slightly decreased compared to the corresponding value for LiMgPO4 (5.60 ​eV). Moreover, the Eg value for LiMg0.74Mn0.26PO4 obtained at 800 ​°C (5.416 ​eV) indicated that higher synthesis temperature resulted in a higher Eg value, from which it could be concluded that Eg restriction could have initiated because of the ratio between the surface areas and the volume of the sample. As expected, the highest PL performance was obtained when Mn-doped newberyite was used as a precursor.