Investigation of phases obtained from the Ce20Ru60Si20 composition

We have studied interaction of components under different heat treatment conditions in a ternary Ce-Ru-Si system starting from the Ce20Ru60Si20 initial composition. The samples were characterized by powder X-ray diffraction and microprobe analysis. The formation of previously reported phases CeRu2Si2 and CeRu3Si2 was confirmed; two possibly novel phases (Ce35Ru58Si7; Ce3Ru2) were detected. A single-phase Ce35Ru58Si7 sample was prepared and its crystal structure was refined from powder diffraction data. Investigations of various physical properties of this material with respect to temperature and magnetic field revealed superconductivity below the critical temperature, Tc = 2.9 K. The nature of the superconducting state is compared to the unconventional superconductivity coexisting with a static magnetic ordering in CeRu2. The formation of ternary phases from the Ce20Ru60Si20 composition is discussed in context of the phases in the Ce-Pt-Si system.