Sr(OH)Br, a Metal Hydroxide Halide with Unusual Properties

Peter, S.; Altorfer, F.; Bührer, W.; Lutz, H. D.

doi:10.1006/jssc.2000.8650

Cited by 9 publications

(10 citation statements)

References 14 publications

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“…f'. As expected, very narrow peaks are observed at ~3600 cm −1 which shift after deuteration. The vibrational wavenumber of free OH ‐ ion is expected to be about the mean value of the symmetric and the antisymmetric stretching wavenumbers of gaseous water molecules, i.e.…”

Section: Resultssupporting

confidence: 82%

“…Usually hydroxyl groups show very sharp IR and Raman stretching modes detected at ~3550–3600 cm −1 because they form vibrators isolated both from the electrical and mechanical point of view . However, the vibrational signature of some hydroxides – this is the case of some earth alkali ones – is much more complex due to the formation of strong H‐bond with water molecules that shifts down the wavenumber and broadens the bands.…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, the dynamic disorder and high protonic diffusion are measured for some (hydr)oxides, in their both solid and molten states, that is at the origin of many confusions in the determination of conducting properties . Comprehensive studies of Ba, Sr, Ca, Mg, … ‐based hydroxides were conducted by Lutz and co‐workers . They pointed out that contrary to the magnesium and calcium hydroxide, which exist in an anhydrous form only, the alkaline earth element hydroxides show polymorphism and form several different hydrates.…”

Section: Introductionmentioning

confidence: 99%

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Aqua oxyhydroxycarbonate second phases at the surface of Ba/Sr‐based proton conducting perovskites: a source of confusion in the understanding of proton conduction

Colomban

Tran

Zaafrani

et al. 2012

J Raman Spectroscopy

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Ba/Sr‐based zirconates and cerates appear as potential proton conducting electrolytes for water electrolysers, hydrogen fuel cells and CO2/syngas converters. Such application requires long lifetime of each components: a good chemical and thermal stability of the device core and a low reactivity of the electrolyte membrane. It has been recently revealed that the complex infrared (IR) and Raman signatures observed for series of zirconates, cerates and/or titanates, assigned by some authors to the bulk protonic species actually arose from the surface species in the form of second undesirable phases: the high dense proton conducting ceramics being free from such signatures. In order to contribute to a better characterization of the phases that can be formed on the surface of proton conducting ceramics, we analysed the IR and Raman spectra of Ba/SrO, Ba/Sr(OH)2, Ba/SrCO3 in their dry and hydrated/deuterated forms in combination with thermogravimetric analysis. The results allowed us to confirm the above claim and to re‐assign the vibrational spectra of perovskite materials wrongly attributed to the bulk protonic species. Since these second phases exhibit a high proton conductivity, their presence is very detrimental in the determination of intrinsic electrolyte bulk properties and interpretation of the conduction mechanisms. Copyright © 2012 John Wiley & Sons, Ltd.

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Section: Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Aqua oxyhydroxycarbonate second phases at the surface of Ba/Sr‐based proton conducting perovskites: a source of confusion in the understanding of proton conduction

Colomban

Tran

Zaafrani

et al. 2012

J Raman Spectroscopy

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“…2) fu È hrte jedoch nur zu einer unwesentlichen Verbesserung der Gu È tefaktoren, obwohl bei Fouriersynthesen mit dem Programm JANA98 [12] zwei Elektronendichtemaxima fu È r Cl(4) erhalten wurden (s. Abb. 2), offensichtlich auf einer Splitlage.…”

Section: Caesiumhexachlorochromat(iii)unclassified

“…Differenzthermoanalysen wurden mit einem DSC7 Difference-Scanning-Calorimeter der Firma Perkin-Elmer [12], Leitfa Èhigkeitsmessungen mit einem Hewlett-Packard 419A LF Impedanzanalyser durchgefu È hrt [13].…”

Section: Introductionunclassified

Caesiumchromhalogenide Cs3CrCl6, Cs3Cr2Cl9 und Cs3CrBr6 - Darstellung, Eigenschaften, Kristallstruktur

Saßmannshausen

Lutz

2001

Z. anorg. allg. Chem.

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Professor Hanskarl Mu È ller-Buschbaum zum 70. Geburtstag gewidmet Inhaltsu È bersicht. Die Kristallstrukturen der Verbindungen Cs 3 CrCl 6 und Cs 3 Cr 2 Cl 9 werden auf der Basis von Ro È ntgeneinkristalldaten bestimmt bzw. nachbestimmt. Cs 3 CrCl 6 kristallisiert in der orthorhombischen Raumgruppe Pnnm (Z = 6) mit den Gitterkonstanten a = 1115,6(2) pm, b = 2291,3(5) pm, c = 743,8(1) pm (R f = 7,73%, 1025 symmetrieunabha È ngige Reflexe mit I > 2r(I)). Die Struktur von Cs 3 CrCl 6 besteht aus zwei verschiedenen, isolierten CrCl 6 -Oktaedern sowie fu È nf kristallographisch verschiedenen Caesiumionen. Die CrCl 6 -Oktaeder bilden Stra È nge in Richtung [001]. Wegen einer Orientierungsfehlordnung der Cr(1)Cl 6 -Oktaeder und der nur 50%igen Besetzung eines Teils der Cs + -und Cl ± -Lagen ist Cs 3 CrCl 6 in Richtung der Netzebene (020) stark fehlgeordnet. Die auf Grund der Fehlordnung erwartete Ionenleitfa È higkeit ist jedoch mit 7,3´10 ±5 X ±1 cm ±1 bei 740 K relativ niedrig. Die in der Literatur beschriebene Kristallstruktur von Cs 3 Cr 2 Cl 9 (P6 3 /mmc, Z = 2; a = 721,7(2) pm und c = 1791,0(1) pm; R f = 2,06%, 395 symmetrieunabha È ngige Reflexe mit I > 2,5r(I)) wurde besta Ètigt. Die bei Raumtemperatur metastabile, mit Cs 3 CrCl 6 wahrscheinlich isotype Verbindung Cs 3 CrBr 6 konnte durch Abschrecken von 833 K dargestellt und ro È ntgenographisch charakterisiert werden.Abstract. The crystal structures of Cs 3 CrCl 6 and Cs 3 Cr 2 Cl 9 were determined and redetermined by X-ray single-crystal studies (space group Pnnm, Z = 6, a = 1115.6(2) pm, b = 2291.3(5) pm, c = 743.8(1) pm, R f = 7.73%, 1025 unique reflections with I > 2r(I) (Cs 3 CrCl 6 ); P6 3 /mmc, Z = 2, a = 721.7(2) pm und c = 1791.0(1) pm; R f = 2.06%, 395 unique reflections with I > 2.5r(I) (Cs 3 Cr 2 Cl 9 ). The structure of Cs 3 CrCl 6 consists of two different isolated CrCl 6 octahedra and five crystallographic different Cs + ions. The CrCl 6 octahedra form ropes in the direction [001]. Because of orientational disordering of the Cr(1)Cl 6 octahedra and the an only half-occupation of some cesium and chlorine sites Cs 3 CrCl 6 is strongly disordered in direction of the (020) plane. The ionic conductivity of Cs 3 CrCl 6 , which was expected owing to the great disorder, however, is with 7.3´10 ±5 X ±1 cm ±1 at 740 K relatively small. The compound Cs 3 CrBr 6 , which was firstly prepared by quenching stoichiometric amounts of CsBr and CrBr 3 from 833 K, is metastable at ambient temperature. It is probably isostructural to Cs 3 CrCl 6 as shown by X-ray powder photographs.

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Proton and Protonic Species: The Hidden Face of Solid State Chemistry. How to Measure H‐Content in Materials?

Colomban

2012

Fuel Cells

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The first objectives of Chemistry are the description of the reactions and the determination of the composition of each compound involved in a process. Solid State Chemistry tries to establish the composition and the structure, the (micro/nano)structure as well as the relationship between composition, structure, and material properties. In the case of Hydrogen element, most of the literature data do not follow this approach: the contents of protons and associated protonic species are rarely measured. Based on the examples of proton conducting materials with different water content: (i) high (sol–gel materials), (ii) medium (polyaniline (PANI) polymer and salts), and (iii) anhydrous (protonated perovskites), we will discuss the main methods (TGA, thermal expansion, infrared and Raman spectroscopy, incoherent (elastic, quasi‐ and in‐elastic) and coherent neutron scattering, neutronography, NRA, RBS/ERDA, ERCS, etc.) able to detect/measure the proton content and/or to identify the nature of the protonic species and their interaction with the host framework: hydroxyl ion, “free” proton, physi/chemi‐sorbed water, strong H‐bonded water, proton hydrates, aquo‐hydroxycarbonates, etc. Emphasis is given to the difficulties encountered for the identification and the quantification of protonic species and the way to overcome them, in particular the discrimination between the surface and bulk moieties.

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Sr(OH)Br, a Metal Hydroxide Halide with Unusual Properties

Cited by 9 publications

References 14 publications

Aqua oxyhydroxycarbonate second phases at the surface of Ba/Sr‐based proton conducting perovskites: a source of confusion in the understanding of proton conduction

Aqua oxyhydroxycarbonate second phases at the surface of Ba/Sr‐based proton conducting perovskites: a source of confusion in the understanding of proton conduction

Caesiumchromhalogenide Cs3CrCl6, Cs3Cr2Cl9 und Cs3CrBr6 - Darstellung, Eigenschaften, Kristallstruktur

Proton and Protonic Species: The Hidden Face of Solid State Chemistry. How to Measure H‐Content in Materials?

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