Crystal structure of Na2HfSi2O7 by Rietveld refinement

International audienceThe structure of triclinic disodium hafnium disilicate, Na 2 HfSi 2 O 7 , has been determined by laboratory powder X-ray diffraction and refined by the Rietveld refinement. The structure is a framework made of alternate layers of HfO 6 octahedra and SiO 4 tetrahedra linked by common O atoms. Sodium atoms are located in the voids of the framework, aligned into tunnels along the [010] direction. Na 2 HfSi 2 O 7 is isostructural with the parakeldyshite Na 2 ZrSi 2 O 7 phase