Dy-0.64{Dy-5[Fe2C9]}: A complex carbide with a composite structure

作者：Davaasuren Bambar; Dashjav Enkhtsetseg^*; Kniep Ruediger; Kreiner Guido; Schnelle Walter; Akselrud Lev; van Smaalen Sander; Woelfel Alexander

来源：Journal of Solid State Chemistry, 2012, 190: 73-79.

DOI：10.1016/j.jssc.2012.02.008

• Ternary carbides
• Rare-earth metals
• Transition metals
• Crystal structure

The ternary carbide Dy-5.64[Fe2C9] has been prepared by high temperature synthesis from the elements. The compound forms as a composite structure with two partial structures, {Dy-5[Fe2C9]} and (Dy-0.64) crystallizing in space groups Pnam and Pbam, respectively. The lattice parameters a=2934.63(9) pm and 6=1263.63(5) pm for the two partial structures are identical, whereas the c lattice parameters for {Dy-5[Fe2C9]} (c(H)=504.14(3) pm) and {Dy-0.64} (c(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(H)/c(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 Dy3 species embedded in a matrix of discrete planar FeC(C-2)(2) units and edge-sharing Fe(C-2)(4) tetrahedra forming infinite chains Fe(C-2)(4/2) running along the c axis.

• 出版日期2012-6