Michael E. Badding

New cerium nitride chlorides : Ce6Cl12N2 and CeNCl

Abstract The compound CeNCl is shown to be isotypic with tetragonal BiOCl with lattice parameters a=b=4.079(2) A , c=6.837(2) A . The compound Ce 6 Cl 12 N 2 was prepared from CeCl 3 , Ce and NaN 3 in a sealed Nb tube at 750 °C. The structure of Ce 6 Cl 12 N 2 was solved by X-ray single crystal diffraction and shown to contain edge-shared, nitrogen-centered, cerium tetrahedra. The lattice parameters for Ce 6 Cl 12 N 2 were determined to be a=11.233(4) A , b=16.527(8) A , c=10.708(3) A , β=90.15° in the spacegroup P2 1 c .

Synthesis and structure of Nb3SiTe6, a new layered ternary niobium telluride compound

Abstract Nb3SiTe6, a new type of layered ternary telluride compound, has been synthesized. The structure is determined by single-crystal X-ray diffraction methods. The compound crystallizes in space group Pnma (No. 62) with Z=4, a=6.353(2) A , b=13.938(5) A , c=11.507(4) A , V=1018.9(6) A 3 , R=4.77% and R w =4.88% . The structure contains sheets of mixed niobium and silicon with tellurium atoms capping both sides. The layered framework has an unusual coordination environment.

Electrical and magnetic properties of tantalum silicon telluride and isostructural compounds

Abstract Electrical resistivity, magnetic susceptibility, and lattice parameter measurements for the family of low-dimensional compounds, M 4 ZTe 4 (M=Ta, Z=Si, Cr, Fe, Co, and Ni; M=Nb, Z=Si, Fe) are reported. The compounds with Z=Si are diamagnetic and the resistivity curves suggest two phase transitions, possibly due to charge density waves in these pseudo one-dimensional systems. For Z=Cr, Fe, Co, and Ni the compounds are paramagnetic metals with characteristics of typical intermetallic phases.

Characterization of TaFe1.25Te3, a new layered telluride with an unusual metal network structure

The new layered material, TaFe1+xTe3 (0.25 < x < 0.29), has been synthesized by reaction of the constituent elements. Single-crystal X-ray diffraction studies show that at x = 0.25 the compound crystallizes in the space group P21m (no. 11) (a = 7.436(1), b = 3.638(1), c = 10.008(1) A, β = 109.17(1)°). The structure features an unusual TaFe bonded network that contains an equal number of Ta and Fe atoms. The metal network lies between tellurium layers, forming a FeTaTe3 “sandwich.” Additionally, x Fe atoms per formula unit partially occupy a square pyramidal site that provides interlayer bonding through the apical tellurium, which is in an adjacent “sandwich.” Selected area electron diffraction studies did not reveal any order in the partially occupied Fe positions. Electrical and magnetic measurements reveal that, at x = 0.25, the compound is an antiferromagnetic metal (TN = 200 K) and undergoes a structural phase transition at 1010 K.

Synthesis, structure and properties of a new intermetallic compound, Ca7Ni4Sn13

Abstract Crystals of a new intermetallic compound, Ca7Ni4Sn13, have been prepared. The refined structure was solved in the P4/m space group, Z = 1 with lattice constants a = 11.200(1) A and c = 4.594(1) A , R = 2.8% and Rw = 2.4%. This new structure type consists of an Sn-Ni network forming channels parallel to the c axis which are filled with calcium atoms. Temperature-dependent magnetic and conductivity studies show Ca7Ni4Sn13 to be Pauli paramagnetic with simple metallic behavior.