Structure and Properties of Hydrogenated Ca, Sr, Ba, and Eu Silicides

Armbruster, Markus; Wörle, Michael; Krumeich, Frank; Nesper, Reinhard

doi:10.1002/zaac.200900220

Cited by 14 publications

(19 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This work describes a much longer Si-D distance of 1.82 Å . Further hydrogenation studies propose the composition CaSiH1.06 [22]. The Rietveld analysis of the corresponding powder X-ray diffraction pattern confirms the heavy metal structure that was originally described.…”

Section: Introductionsupporting

confidence: 73%

“…The anisotropic broadening effect can be sufficiently described by the two parameters S400 and S004 with a fixed profile mixing parameter of 1.0 (pure Lorentzian type) and might arise from anisotropic crystallite size broadening. A previous report states that the compound tends to delaminate perpendicular to the crystallographic a axis as determined from SEM images [22]. Since the polyanions run along the crystallographic b direction, it appears reasonable that (0k0) reflections are the sharpest ones.…”

Section: Bragg Diffraction and Rietveld Analysismentioning

confidence: 77%

See 1 more Smart Citation

Covalent Si–H Bonds in the Zintl Phase Hydride CaSiH1+x (x ≤ 1/3)

et al. 2019

View full text Add to dashboard Cite

The crystal structure of the Zintl phase hydride CaSiH≈4/3 was discussed controversially, especially with respect to the nature of the silicon-hydrogen interaction. We have applied X-ray and neutron powder diffraction as well as total neutron scattering on a deuterated sample, CaSiD1.1. Rietveld refinement (CaSiD1.1, Pnma, a = 14.579(4) Å, b = 3.8119(4) Å, c = 11.209(2) Å) and an analysis of the neutron pair distribution function show a silicon-deuterium bond length of 1.53 Å. The Si–H bond may thus be categorized as covalent and the main structural features described by a limiting ionic formula Ca2+H−(Si−)2/3(SiH−)1/3. Hydrogen atoms decorating the ribbon-like silicon polyanion made of three connected zigzag chains are under-occupied, resulting in a composition CaSiH1.1. Hydrogen-poor Zintl phase hydrides CaSiH<1 with hydride ions in Ca4 tetrahedra only were found in an in situ neutron diffraction experiment at elevated temperature. Hydrogen (deuterium) uptake and release in CaSiDx (0.05 ≤ x ≤ 0.17) is a very fast process and takes less than 1 min to complete, which is of importance for possible hydrogen storage applications.

show abstract

Section: Introductionsupporting

confidence: 73%

Section: Bragg Diffraction and Rietveld Analysismentioning

confidence: 77%

Covalent Si–H Bonds in the Zintl Phase Hydride CaSiH1+x (x ≤ 1/3)

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The crystal structure is clearly stabilized by strong ionic bonding from additional hydride ions in Ae 4 tetrahedra (Figure ). Crystal structure (for both) and hydrogen content (for the BaSi hydrides) contradict an earlier report of hydrides of Ae Si Zintl phases, where, however, hydrogen positions were not determined . The crystal structure shows a close relationship to the parent Zintl phase.…”

Section: Figurementioning

confidence: 99%

Structural and Electronic Flexibility in Hydrides of Zintl Phases with Tetrel–Hydrogen and Tetrel–Tetrel Bonds

2017

View full text Add to dashboard Cite

The hydrogenation of Zintl phases enables the formation of new structural entities with main-group-element-hydrogen bonds in the solid state. The hydrogenation of SrSi, BaSi, and BaGe yields the hydrides SrSiH BaSiH and BaGeH . The crystal structures show a sixfold superstructure compared to the parent Zintl phase and were solved by a combination of X-ray, neutron, and electron diffraction and the aid of DFT calculations. Layers of connected HSr (HBa ) tetrahedra containing hydride ions alternate with layers of infinite single- and double-chain polyanions, in which hydrogen atoms are covalently bound to silicon and germanium. The idealized formulae AeTtH (Ae=alkaline earth, Tt=tetrel) can be rationalized with the Zintl-Klemm concept according to (Ae ) (TtH )(Tt H )(H ) , where all Tt atoms are three-binding. The non-stoichiometry (SrSiH , x=0.17(2); BaGeH , x=0.10(3)) can be explained by additional π-bonding of the Tt chains.

show abstract

“…Though hydrogenated Zintl phases had occasionally, been described over the decades such reports remained of more or less a sporadic nature 69. Systematic hydrogenation of Zintl phase which should have been a consequent development from the experience of hydrogenation of alloy systems has been targeted only quite recently 70–73…”

Section: Charge Stabilization In Multiple Salt Compoundsmentioning

confidence: 99%

The Zintl‐Klemm Concept – A Historical Survey

Nesper¹

2014

Zeitschrift anorg allge chemie

Self Cite

194

150

View full text Add to dashboard Cite

The Zintl‐Klemm concept (ZKC) is a combination of a valence electron counting rule and a set of structure‐chemical considerations which works well for a continuously growing class of compounds between classical salts and classical covalent compounds on the on hand, and intermetallic phases on the other. In this historical article the lines of development of the ZKC are reviewed. They originate from Eduard Zintl in Darmstadt and were carried on and extended by Wilhelm Klemm in Münster, early on. After World War II different schools developed their own points of view on the ZKC which converged in the 1990s, backed by blossoming quantum mechanical schemes of treating complex solids. The limits of applicability of the ZKC are subject of ongoing investigations, still, and it seems that the concept has reached a state of quite general acceptance in solid state sciences.

show abstract

Structure and Properties of Hydrogenated Ca, Sr, Ba, and Eu Silicides

Abstract: The binary metal silicides CaSi, BaSi, SrSi, and EuSi that crystallize in the CrB type absorb reversibly hydrogen. Hydrogen con-

Cited by 14 publications

References 40 publications

Covalent Si–H Bonds in the Zintl Phase Hydride CaSiH1+x (x ≤ 1/3)

Covalent Si–H Bonds in the Zintl Phase Hydride CaSiH1+x (x ≤ 1/3)

Structural and Electronic Flexibility in Hydrides of Zintl Phases with Tetrel–Hydrogen and Tetrel–Tetrel Bonds

The Zintl‐Klemm Concept – A Historical Survey

Contact Info

Product

Resources

About