Synthesis, structure and bonding of Gd 6MTe 2 (M=Co, Ni), Er 6RuTe 2

Abstract

Three new rare earth metal-rich compounds, Gd 6MTe 2 (M=Co, Ni) and Er 6RuTe 2, were synthesized in direct reactions between the R, R 3M, and R 2Te 3 (R=Gd, Er, M=Co, Ni, Ru). These materials all adopt the same Zr 6CoAl 2 structure type with space group P 62m (No. 189, Z=1). Single crystal structures of Gd 6CoTe 2 and Er 6RuTe 2 were determined and lattice parameters are a= b=8.3799(5), c=3.9801(4) Å, and a= b=8.1473(5) Å, c=3.9962(4) Å, respectively. Gd 6NiTe 2 was characterized by X-ray powder diffraction; lattice parameters are a= b=8.412(2), c=3.9577(9) Å. Metal–metal bonding correlations were analyzed using the empirical Pauling bond order concept.