Structural Phase Transitions and Crystal Structure for Na3D(SO4)2 Crystals at Room Temperature

Abstract

Differential scanning calorimetry and X-ray diffraction measurements were performed on deuterated trisodium hydrogen disulphate, Na3D(SO4)2, crystals. Two structural phase transitions are found at around 195(2) K and 540.3(5) K. The space group symmetry (monoclinic P21/c) and the crystal structure of Na3D(SO4)2 are determined at 295 K. The isotope effect for the hydrogen bond of Na3H(SO4)2 is discussed.