Anion reorientation in anhydrous Na3PO4 during the phase transformation

The transport phenomena in alkali-metal super ionic conductors based on Na₃PO₄ structure are of particular interest due to their potential technological application. Differential thermal analysis (DTA), differential scanning calorimetry (DSC), Raman spectroscopy and temperature dependent electrical conductivity measurements were carried out to probe the nature of the phase transformation involved in anhydrous Na₃PO₄. The changes in spectral profile of the v₃ mode and the line width of v₁ mode of PO ₄ ³⁻ observed in the temperature interval from 331 to 345 °C revealed the high degree of disorder nature during the α-γNa₃PO₄ phase transformation. Paper presented at the 2nd Internation Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003.