Phase transformations in LiH2PO4 (LDP) revealed by Raman spectroscopy

We investigate Raman scattering measurements on polycrystalline LiH2PO4 (LDP) between 30 and 240 °C, in order to detect phase transformations. The thermal behavior of main lines in different wavenumber ranges is discussed and analyzed. Raman spectra show two anomalies at 176 °C and 210 °C, reflecting changes in chemical bonds, and are attributed to progressive polymerization, in agreement with earlier electrical measurements.