Dy{sub 0.64}{l_brace}Dy{sub 5}[Fe{sub 2}C{sub 9}]{r_brace}: A complex carbide with a composite structure

Journal Article · Fri Jun 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.02.008· OSTI ID:22012127

Davaasuren, Bambar ^[1]; Dashjav, Enkhtsetseg ^[1]; Kniep, Ruediger ^[1]; Kreiner, Guido ^[1]; Schnelle, Walter ^[1]; Akselrud, Lev ^[2]; Smaalen, Sander van; Woelfel, Alexander ^[3]

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1. Max-Planck-Institut fuer Chemische Physik fester Stoffe, Noethnitzer Strasse 40, 0118 Dresden (Germany)
2. Ivan Franko National University of Lviv, Kyrylo and Methody Street 6, 79005 Lviv (Ukraine)
3. Laboratory of Crystallography BGI Building, University of Bayreuth, Universitaetsstrasse 30, D-95440 Bayreuth (Germany)

The ternary carbide Dy{sub 5.64}[Fe{sub 2}C{sub 9}] has been prepared by high temperature synthesis from the elements. The compound forms as a composite structure with two partial structures, {l_brace}Dy{sub 5}[Fe{sub 2}C{sub 9}]{r_brace} and {l_brace}Dy{sub 0.64}{r_brace} crystallizing in space groups Pnam and Pbam, respectively. The lattice parameters a=2934.63(9) pm and b=1263.63(5) pm for the two partial structures are identical, whereas the c lattice parameters for {l_brace}Dy{sub 5}[Fe{sub 2}C{sub 9}]{r_brace} (c{sub H}=504.14(3) pm) and {l_brace}Dy{sub 0.64}{r_brace} (c{sub G}=1056.01(5) pm) are different. This gives rise to a modulated structure in the (3+1)D superspace group Pnam(00g) with q=c{sub H}/c{sub G}=0.4775. The refinement converged to R(F) values below 0.055 for each partial structure using harmonic and Crenel functions. The compound is a bad metallic conductor and represents a new structure type composed of Dy{sup 3+} species embedded in a matrix of discrete planar FeC(C{sub 2}){sub 2} units and edge-sharing Fe(C{sub 2}){sub 4} tetrahedra forming infinite chains Fe(C{sub 2}){sub 4/2} running along the c axis. - Graphical abstract: Dy guest atoms (green) within an carbon octahedral channel of the modulated structure together with a tetrahedral Fe(C{sub 2}){sub 4/2} chain and triangular planar FeC(C{sub 2}){sub 2} groups in the crystal structure of Dy{sub 0.64}{l_brace}Dy{sub 5}[Fe{sub 2}C{sub 9}]{r_brace}. Highlights: Black-Right-Pointing-Pointer The first successful refinement of a large composite structure Dy{sub 0.64}{l_brace}Dy{sub 5}[Fe{sub 2}C{sub 9}]{r_brace}. Black-Right-Pointing-Pointer The presence of two kinds of complex anions with Fe as central atoms and C-ligands within this structure. Black-Right-Pointing-Pointer The oxidation state of the Fe atoms are low, they can be assigned Fe{sup I} and Fe{sup II}.

• OSTI ID: 22012127
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. . 190; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CARBIDES
COMPLEXES
CRYSTAL STRUCTURE
DYSPROSIUM IONS
LATTICE PARAMETERS
LIGANDS
RARE EARTHS
SPACE GROUPS
SYNTHESIS
TRANSITION ELEMENTS