title: In Situ Hydrogenation of the Zintl Phase SrGe.
abstract: Hydrides (deuterides) of the CrB-type Zintl phases AeTt (Ae = alkaline earth; Tt = tetrel) show interesting bonding properties with novel polyanions. In SrGeD4/3-x(γ phase), three zigzag chains of Ge atoms are condensed and terminated by covalently bound D atoms. A combination of in situ techniques (thermal analysis and synchrotron and neutron powder diffraction) revealed the existence of two further hydride (deuteride) phases with lower H (D) content (called α and β phases). Both are structurally related to the parent Zintl phase SrGe and to the ZrNiH structure type containing variable amounts of H (D) in Sr4tetrahedra. For α-SrGeDy, the highest D content y = 0.29 was found at 575(2) K under 5.0(1) MPa of D2pressure, and β-SrGeDyshows a homogeneity range of 0.47 < y < 0.63. Upon decomposition of SrGeD4/3-x(γ-SrGeDy), tetrahedral Sr4voids stay filled, while the Ge-bound D4 site loses D. When reaching the lower D content limit, SrGeD4/3-x(γ phase) with 0.10 < x < 0.17, decomposes to the β phase. All three hydrides (deuterides) of SrGe show variable H (D) content.
authors.affiliation: Department of Inorganic Chemistry, Leipzig University , Johannisalle 29, 04103 Leipzig, Germany.
authors.forename: Henry
authors.identifier: http://orcid.org/0000-0002-8624-4617
authors.initials: H
authors.lastname: Auer
authors.affiliation: Helmholtz Zentrum Berlin für Materialien und Energie , Hahn-Meitner-Platz 1, 14109 Berlin, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Wallacher
authors.affiliation: Institut Laue-Langevin , 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France.
authors.forename: Thomas Christian
authors.initials: TC
authors.lastname: Hansen
authors.affiliation: Department of Inorganic Chemistry, Leipzig University , Johannisalle 29, 04103 Leipzig, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Kohlmann