Peter E. Childs
Bio: Peter E. Childs is an academic researcher from University of York. The author has contributed to research in topics: Uranyl & Proton transport. The author has an hindex of 1, co-authored 1 publications receiving 57 citations.
TL;DR: In this article, the authors measured the relaxation times in hydrogen uranyl phosphate and arsenate, which are fast proton conductors, and found that the two compounds undergo a phase transition resulting in discontinuities in T/sub 1/ and t/sub 2/ and a DTA peak.
TL;DR: In this paper, a Grotthus-type mechanism of conduction is proposed which involves intermolecular transfer steps (hopping) and inter-parallel transfer steps in comparable numbers, the former facilitated by the high concentration of H 3 O + ions in the structure, and the latter most likely facilitated by high H-bond vacancies.
TL;DR: In this paper, single-crystal measurements on hydrogen uranyl phosphate tetrahydrate, HUO 2 PO 4 ·4H 2 O (HUP), have confirmed that the high proton conductivity is a bulk characteristic.
TL;DR: In this article, the structural roles of the interlayer cations in determining the symmetries and hydration states observed are discussed, and the smallest monovalent cation, Li, occurs in tetra- hedral coordination between fourfold squares of hydrogen-bonded H2O groups.
Abstract: Compounds of the meta-autunite group containing monovalent cations (Li, Na, K, Rb, Cs, Ag, Tl) have been synthesized by diffusion in gels or by hydrothermal methods, and their crystal structures determined. Single-crystal X-ray-diffraction intensity data were collected at room temperature using MoKradiation and a CCD-based area detector. These compounds contain the autunite-type sheet with composition ((UO2)(XO4)) - , X = P or As, which involves the sharing of equatorial vertices of uranyl square bipyramids with tetrahedra. The interlayer region contains cations and H2O groups, and the sheets are linked by hydrogen bonding and through bonds from the interlayer cations to oxygen atoms of the sheets. The structural roles of the interlayer cations in determining the symmetries and hydration states observed are discussed. The smallest monovalent cation, Li, occurs in tetra- hedral coordination between fourfold squares of hydrogen-bonded H2O groups. Despite a wide range in ionic radius, Na, K, Rb, Ag and Tl randomly substitute for H2O groups in the interlayer, in the same fashion as their ammonium and oxonium analogues. The large Cs cation adopts independent crystallographic sites in the interlayer. The size difference between Cs and the other monovalent cations probably prevents their direct substitution, and may limit the extent of solid solution. With the exception of
TL;DR: In this paper, the authors reported the NMR relaxation times (T2 T1, and T1ϱ) and absorption spectra for the compounds H1.71MoO3 (red monoclinic) and H0.36MoO 3 (blue orthorhombic) in the temperature range 77 K < T < 450 K.
TL;DR: In this article, the authors measured the ionic conductivities of pressed pellets of the layered compounds MUO2PO4 · nH2O, and correlated the results with TGA data.