Crystal structure of a new HfO(OH)₂ oxyhydroxide

Abstract

The crystal structure of a new hafnium oxyhydroxide obtained by an ion-exchange reaction from a Li 2 HfO 3 precursor has been solved by a direct method and refined using Rietveld full profile fitting based on X-ray powder diffraction data. HfO(ОН) 2 crystallizes in a P2 1 /c monoclinic unit cell (a = 5.5578(5) Å, b = 9.0701(10) Å, c = 5.7174(5) Å, β = 119.746(5)°); its structure can be described as a framework formed by edge-sharing HfO 6 octahedra connected to each other via vertices. In addition, an analysis of the atomic pair distribution function obtained using synchrotron radiation was used to confirm the model and to describe fine-structure features.

Anisotropic Diffusion of a Charged Tritium Interstitial in Li2TiO3 from First-Principles Calculations

“…In this work, we focus on the monoclinic β-phase Li 2 TiO 3 , which is stable throughout the operating temperature range of a breeder material [28,29]. The single-crystal Li 2 TiO 3 can be characterized by a C2/c space group with lattice parameters: a = 0.50623 nm, b = 0.87876 nm, c = 0.97533 nm, and β = 100.212°, determined experimentally at 295 K by Kataoka, et al [28] The crystal structure of Li 2 TiO 3 features the stacking sequence -(Li 6 -O 6 -Li 2 Ti 4 -O 6 )-along the 001 direction.…”

COF-supported zirconium oxyhydroxide as a versatile heterogeneous catalyst for Knoevenagel condensation and nerve agent hydrolysis

“…Although single crystal X-ray structure of La 0.26 Bi 0.74 OOH is reported, 27 most other oxyhydroxides structures have been solved from powder X-ray diffraction (PXRD) using Rietveld methods. 23 , 28 However, to the best of our knowledge, the crystal structure of ZrO x (OH) y is not known and it forms as an amorphous material, which at higher temperatures oxidizes to ZrO 2 . 26 …”