Incoherent inelastic neutron scattering studies of proton conducting materials trivalent metal acid sulphate hydrates

In order to clarify certain aspects concerning the assignment of bands in the vibrational spectrum of the dihydrated proton H5O2+, the incoherent inelastic neutron scattering spectra of three inorganic compounds containing this ion have been recorded. The spectrum of HClO4·2H2O, obtained at 77 K, unambiguously reflects one type of ordered H5O2+ ion, and contains no contribution from the counterion. Those of the layer structured proton conductors HFe(SO4)2·4H2O and HIn(SO4)2·4H2O, recorded at 20 K, are consistent with the presence of H5O2+ as the only mobile protonic species. The spectra have been fully assigned in terms of vibrations, librations and translations of H5O2+. © 1989

Incoherent inelastic neutron scattering studies of proton conducting materials: Sn(HPO₄)₂·H₂O and HM(SO₄)₂·H₂O,M=Fe

The vibrational spectra of the proton conductors Sn(HPO4)2·H2O, HFe(SO4)2·H2O, and HIn(SO4)2·H2O have been investigated by incoherent inelastic neutron-scattering spectroscopy at 20 K. Torsional and other rotational motion and internal deformation modes of H3O+ have been identified in the trivalent metal acid sulphate monohydrates. The spectroscopic data on Sn(HPO4)2·H2O are consistent with the presence of covalent POH hydrogen bonded to the water molecule. © 1989

On Electrospinning of PFSA: A Comparison between Long and Short-Side Chain Ionomers

International audienc

THE APPLICATION OF EXAFS SPECTROSCOPY TO THE STRUCTURAL DETERMINATION OF FLUORITE TYPE OXYGEN- EXCESS URANIUM OXIDES AND OF MIXED (U,Ce) OXIDES

On a utilisé l'EXAFS pour UO2, β-U3O7 (=UO2.33) et U4O9 (=UO2.25) au seuil de l'uranium, ainsi qu'aux seuils de l'uranium et du cérium pour la série (U1-y,Cey)O2-x, x=7,20,28% pour caractériser l'environnement autour de l'uranium et de cérium et de déterminer la répartition des défauts dans les phases nonstoechiométriques.EXAFS spectroscopy has been carried out at 77 K at the uranium LIII edge of UO2, β-U3O7 (=UO2.33) and U4O9 (=UO2.25), and at both the uranium and cerium edges in the series of mixed oxides (UyCe1-y)O2-x x=7,20,28%, with the aim of determining the structure of these highly defective phases