Synthesis, structure, and physical properties of the new layered ternary telluride TaPtTe5

The new ternary telluride TaPtTe5 has been prepared. It is a metallic, layered material whose structure has been determined by single-crystal X-ray diffraction methods. TaPtTe5 is isostructural with NbNiTe5 and TaNiTe5. It crystallizes in space group D172h-Cmcm of the orthorhombic system with four formula units in a cell of dimensions a = 3.729(4), b = 13.231(11), c = 15.452(10) Å. The layers consist of bicapped trigonal prismatic Ta atoms and octahedral Pt atoms coordinated by Te atoms. TaPtTe5 displays good metallic conductivity along the a axis (σ298 = 9.7 × 104 Ω−1cm−1) and is Pauli-paramagnetic (χ = 2.1 × 10−4 emu mol−1). The electrical and magnetic properties of TaPtTe5 are compared with those of NbNiTe5 and TaNiTe5, as well as with the related compound NbPdTe5. NbPdTe5 contains layers identical with those of the present series of compounds but stacked differently; it is a relatively poor metallic conductor.