Synthesis, characterization, vibrational spectroscopy, and factor group analysis of partially metal-doped phosphate materials.

A simple precipitating method was used to synthesize effectively a partially metal-doped phosphate hydrate (MnMgHPO·3HO), whereas the thermal decomposition process of the above hydrate precursor was used to obtain MnMgPO and LiMnMgPO compounds under different conditions. To separate the overlapping thermal decomposition peak, a deconvolution technique was used, and the separated peak was applied to calculate the water content. The factor group splitting analysis was used to exemplify their vibrational spectra obtained from normal vibrations of HPO, HO, PO and PO functional groups. Further, the deconvoluted bending mode of water was clearly observed. MnMgHPO·3HO was observed in the orthorhombic crystal system with the space group of Pbca (D). The formula units per unit cell were found to be eight (Z = 8), and the site symmetric type of HPO was observed as C. For the HPO unit, the correlation filed splitting analysis of type C - C - D was calculated and had 96 internal modes, whereas HO in the above hydrate was symbolized as C - C - D and had 24 modes. The symbol C - C - C was used for the correlation filed splitting analysis of PO in MnMgPO (monoclinic, C2/m (C), Z = 2, and 42 modes). Finally, the symbol T - C - D was used for the correlation filed splitting analysis of PO in LiMnMgPO (orthorhombic, Pnma (D), Z = 4, and 36 modes).