% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Kazem:189315, author = {Kazem, Nasrin and Hurtado, Antonio and Klobes, Benedikt and Kauzlarich, Susan M. and Hermann, Raphael}, title = {{E}u$_{9}${C}d$_{4–x}${CM}$_{2+x–y□y}${S}b$_{9}$: {C}a$_{9}${M}n$_{4}${B}i$_{9}$-{T}ype {S}tructure {S}tuffed with {C}oinage {M}etals ({C}u, {A}g, and {A}u) and the {C}hallenges with {C}lassical {V}alence {T}heory in {D}escribing {T}hese {P}ossible {Z}intl {P}hases}, journal = {Inorganic chemistry}, volume = {54}, number = {3}, issn = {1520-510X}, address = {Washington, DC}, publisher = {American Chemical Society}, reportid = {FZJ-2015-02493}, pages = {850 - 859}, year = {2015}, abstract = {The synthesis, crystal structure, magnetic properties, and europium Mössbauer spectroscopy of the new members of the 9–4–9 Zintl family of Eu9Cd4–xCM2+x–y□ySb9 (CM = coinage metal: Au, Ag, and Cu) are reported. These compounds crystallize in the Ca9Mn4Bi9 structure type (9–4–9) with the 4g interstitial site almost half-occupied by coinage metals; these are the first members in the 9–4–9 family where the interstitial positions are occupied by a monovalent metal. All previously known compounds with this structure type include divalent interstitials where these interstitials are typically the same as the transition metals in the anionic framework. Single-crystal magnetic susceptibility data indicate paramagnetic behavior for all three compounds with antiferromagnetic ordering below 10 K (at 100 Oe) that shifts to lower temperature (<7 K) by applying a 3 T magnetic field. 151Eu Mössbauer spectra were collected on polycrystalline powder samples of Eu9Cd4–xCM2+x–y□ySb9 at 50 and 6.5 K in order to evaluate the valence of Eu cations. Although the Zintl formalism states that the five crystallographically distinct Eu sites in Eu9Cd4–xCM2+x–y□ySb9 should bear Eu2+, the Mössbauer spectral isomer shifts are clearly indicative of both 2+ and 3+ valence of the Eu cations with the Cu- and Au-containing compounds showing higher amounts of Eu3+. This electronic configuration leads to an excess of negative charge in these compounds that contradicts the expected valence-precise requirement of Zintl phases. The spectra obtained at 6.5 K reveal magnetic ordering for both Eu2+ and Eu3+. The field dependence of Eu2+ indicates two distinct magnetic sublattices, with higher and lower fields, and of a small field for Eu3+. The site symmetry of the five Eu sites is not distinguishable from the Mössbauer data.}, cin = {JCNS-2 / PGI-4 / JARA-FIT}, ddc = {540}, cid = {I:(DE-Juel1)JCNS-2-20110106 / I:(DE-Juel1)PGI-4-20110106 / $I:(DE-82)080009_20140620$}, pnm = {144 - Controlling Collective States (POF3-144) / 524 - Controlling Collective States (POF3-524) / 6213 - Materials and Processes for Energy and Transport Technologies (POF3-621) / 6G4 - Jülich Centre for Neutron Research (JCNS) (POF3-623) / 6212 - Quantum Condensed Matter: Magnetism, Superconductivity (POF3-621)}, pid = {G:(DE-HGF)POF3-144 / G:(DE-HGF)POF3-524 / G:(DE-HGF)POF3-6213 / G:(DE-HGF)POF3-6G4 / G:(DE-HGF)POF3-6212}, typ = {PUB:(DE-HGF)16}, UT = {WOS:000348887400021}, pubmed = {pmid:25354329}, doi = {10.1021/ic502061w}, url = {https://juser.fz-juelich.de/record/189315}, }