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Ternary metal hydrides

Ternary metal hydrides have the general formula (A = alkali [Pg.268]

The transition metal compounds are usually made by either reaction of the elements or reaction of an alkali metal hydride and the metal at elevated temperature and pressure. Very high temperatures and pressures (770 K and 1500-1800 bar) result in the formation of high oxidation states of second and third row transition metals. The materials have been extensively characterised by X-ray and neutron diffraction and several reviews are available [72,73,74,75]. There is a large diversity of structural types but the central ion generally has the classical [Pg.269]

At room temperature Mg2[FeHg] crystallizes in the cubic space group FmSmsC (number 225) with four molecules in the unit cell. There is one formula unit in the Bravais cell and the ions all lie on special sites the Mg ions on tetrahedral sites and the [FeHe] ions on octahedral Ob sites. Using the correlation method [77] we can classify the vibrations as in Table 6.11. In Fig. 6.24 we show the infi-ared, Raman and INS spectra of Mg2[FeHe]. [Pg.269]

The assignment of the stretching modes is more complicated than might be expected. The band at 1873 cm in the Raman and INS spectra [Pg.269]

In the Raman spectrum, the mode is usually much weaker than the ig mode, so the failvue to observe it, is not surprising however, it should have significant INS intensity but only two bands are observed. We note that the ratio of the intensities of the Eg and Tiu modes should be approximately 1 2 3. Thus for the INS feature at 1878 cm to [Pg.270]


K Yvon, B. BertheviUe, Magnesium based ternary metal hydrides containing alkali and alkaline-earth elements, J. Alloys Compd. 425 (2006) 101-108. [Pg.191]

This volume summarizes recent results of some of the leading investigators in trahsition metal hydride research. Readers interested in more extensive background material are urged to consult some of the many excellent books on the subject, such as Transition Metal Hydrides edited by E. L. Muetterties (Marcel Dekker, Inc., New York, 1971), which covers covalent metal hydride complexes, and Metal Hydrides edited by W. M. Mueller, J. P. Blackledge, and G. G. Libowitz (Academic, New York, 1968), which comprehensively covers work in binary and ternary metal hydrides. Also available in the covalent metal hydride area are excellent reviews by Ginsberg [Transition Metal Chemistry (1965) 1,112], and Kaesz and Saillant [Chemical Reviews (1972) 72, 231]. In this book we have not tried to be comprehensive rather, our purpose is to update recent developments in both major areas of metal hydride research. [Pg.7]

Ternary Metal Hydrides as Chemical Heat Pumps... [Pg.336]

Ternary metal hydrides of formula A2MH6 (A = Mg, Ca, Sr, Eu and M = Fe, Ru and Os) are known. Full characterization requires knowledge of the distribution of the H atoms within the structure of the A2M host. Using what we have learned, let s try to deduce their arrangement employing Mg2FeH6 as an example. [Pg.287]

Up to now, research on ternary metal hydrides based on magnesium and alkaline or alkaline earth metals has not produced alloys with practical hydrogen storage characteristics [250]. However, study of quaternary alloys is a new fleld that is worth investigating and could give practical hydrogen storage systems [250]. [Pg.107]

Table 6.12 Ternary metal hydrides studied by INS spectroscopy. Table 6.12 Ternary metal hydrides studied by INS spectroscopy.
Table 6.13 Infrared active metal-hydride stretch and bend frequencies (o>/ cm ) of octahedral ternary metal hydrides. Table 6.13 Infrared active metal-hydride stretch and bend frequencies (o>/ cm ) of octahedral ternary metal hydrides.
S.F. Parker, K.P.J. Williams, T. Smith, M. Bortz, B. Bertheville K. Yvon (2002). Phys. Chem. Chem. Phys., 4, 1732-1737. Vibrational spectroscopy of tetrahedral ternary metal hydrides Mg2[NiH4], Rb3[ZnH5] and their deuterides. [Pg.282]

Yvon, K. and Fisher, R, Crystal structure and magnetic structures of ternary metal hydride a comprehensive review, in Hydrogen in Intermetallic Compounds I Electronic, Thermodynamic, and Crystallographic Properties, Preparation, L. Schlapbach, Editor. 1988, Springer Verlag Berlin, p. 88-138. [Pg.352]


See other pages where Ternary metal hydrides is mentioned: [Pg.172]    [Pg.7]    [Pg.315]    [Pg.172]    [Pg.298]    [Pg.267]    [Pg.267]    [Pg.268]    [Pg.269]    [Pg.243]    [Pg.163]    [Pg.186]    [Pg.468]   


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Early Studies of Noninterstitial Transition Metal Ternary Hydrides

Hydride ternary

Magnesium-based ternary metal hydrides

Noninterstitial transition metal ternary hydrides

Ternary transition metal complex hydrides

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