A systematic study was conducted of pure Na3PO4 and solid solutions of Na3PO4 doped with Mg2+ and Zn2+. Na3PO4 has two solid phases: a low-temperature tetragonal phase and a high-temperature cubic phase. A factor group analysis of the two phases yielded the expected number of modes and their symmetry-based assignments. A temperature-dependent Raman spectroscopic study was then performed for the pure compound. Analysis of the doped Na3PO4 has also provided another description of the local structural distortions present in the cubic structure. (C) 2000 American Institute of Physics. [S0021-9606(00)01906-1].