Intermetallics La9Ru4In5 and Ce9Ru4Ga5 with new types of structures. Synthesis, crystal structures, physical properties

Intermetallics La9Ru4In5 and Ce9Ru4Ga5 were synthesized by arc melting of the elemental components with subsequent annealing at 600 °C. The crystal structures were determined from X-ray single-crystal diffraction data. The compounds belong to new structural types: Ce9Ru4Ga5 crystallizes in space group I4mm, Z = 2, a = 10.1132(4), c = 8.1212(3) Å, La9Ru4In5 crystallizes in space group I4/mmm, Z = 2, a = 10.604(3), c = 8.535(5) Å. The short Ce–Ru distance of 2.366 Å is an interesting feature of the Ce9Ru4Ga5 structure; this phenomenon is caused by intermediate valence state of cerium atoms. The experimental L3-Ce XANES spectroscopy data show that the average valence of Ce in intermetallic Ce9Ru4Ga5 is about ∼3.10 at 7 °C.