Preparation de la solution solide hydrurofluoree CaF2−xHx (0 &lt; x ⩽ 1,24) etude structurale par diffraction des rayons X et par diffraction des neutrons

Brice, J.F.; Courtois, A.; Aubry, J.

doi:10.1016/0022-4596(78)90030-0

Cited by 27 publications

(21 citation statements)

References 12 publications

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“…Considering as an example the CaH 2 -CaF 2 system, an orthorhombic (hydride structure) and a cubic (fluoride structure) solid solution have been modelled [22]. As shown in figure 2e, according to ab initio calculations, the enthalpy of mixing in the cubic solid solution is slightly negative, whereas a positive value is calculated for the It is worth to note that the free energy difference between cubic and orthorhombic CaH 2 is rather small (ΔH m-s = 6.8 kJ•mol H2 -1 and ΔS m-s = 0.3 J•mol H2 -1 •K -1 ), promoting the solubility of H into solid CaF 2 , as confirmed by experimental investigations [22,23].…”

Section: Resultsmentioning

confidence: 72%

Effects of metastability on hydrogen sorption in fluorine substituted hydrides

Pinatel

Corno

Ugliengo

et al. 2014

Journal of Alloys and Compounds

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In this work ab initio calculations and Calphad modelling have been coupled to describe the effect of fluorine substitution on the thermodynamics of hydrogenation-dehydrogenation in simple hydrides (NaH, AlH3 and CaH2). These example systems have been used to discuss the conditions required for the formation of a stable hydride-fluoride solid solution necessary to obtain a reversible hydrogenation reaction. • PRIME NOVELTY STATEMENT In the submitted manuscript, we are reporting new results obtained coupling ab initio calculations with Calphad modeling. The goal is to describe the effect of fluorine substitution on the thermodynamics of hydrogenation-dehydrogenation in simple hydrides. NaH-NaF, CaH2-CaF2 and AlH3-AlF3 systems have been used as examples to describe the conditions required for the formation of a stable hydride-fluoride solid solution. Parameters necessary to obtain a reversible sorption reaction have been discussed. Prime Novelty Statement• AUTHORSHIP STATEMENT The submission of the manuscript has been approved by all co-authors Reply to referee's commentsThe authors acknowledge the referee for useful comments. In the following, specific answers are provided. General CommentsThe manuscript reports on modelling studies (ab-initio and CALPHAD) (Brinks et al, J. Phys Chem C 112, 2008, 5658-5661). The authors should include this reference in the introduction.Suggested reference has been introduced in the text. *) Modelling. Please provide reference for Eq. (2)A reference for Eq. (2) has been provided. English has been revised. The last sentence of page 1 has been shortened. *) As mention in the general

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Section: Resultsmentioning

confidence: 72%

Effects of metastability on hydrogen sorption in fluorine substituted hydrides

Pinatel

Corno

Ugliengo

et al. 2014

Journal of Alloys and Compounds

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“…This limited substitution makes a good contrast with a solid solution formation in CaH 2 -CaF 2 system [39]. One of the reasons lies in a different character of H in Ca(BH 4 ) 2 and in CaH 2 .…”

Section: Phase Compositions Of Starting Materialsmentioning

confidence: 96%

“…[46][47][48] are not clearly seen. CaH 2 is stable in an orthorhombic structure (space group Pnma), but extensive solubility in the cubic CaF 2 structure (space group Fm-3m) has been reported [39]. The H fraction in the F site can be estimated from the relative peak intensities.…”

Section: Decomposition Reactionmentioning

confidence: 99%

Metal halide doped metal borohydrides for hydrogen storage: The case of Ca(BH4)2–CaX2 (X = F, Cl) mixture

Lee

Suh

et al. 2010

Journal of Alloys and Compounds

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“…Table 2 The crystal structures and the lattice parameters of the refined structures in Figure 2. Solid solutions of CaH 2-x F x in the cubic CaF 2 crystal structure with various concentrations of hydrogen have previously been reported, first by Brice et al [63] and more recently in connection with research on Ca(BH 4 ) 2 thermal decomposition [64,65]. Smithson et al [66] have performed ab-initio calculations that show that at zero pressure, the formation energies for orthorhombic CaH 2 and cubic CaH 2 are very similar.…”

Section: Cah 2 Formationmentioning

confidence: 99%