Evolution of structural, magnetic, and electrical transport properties in Ru-doped pyrochlore iridate Eu 2 Ir 2 O 7

We report the evolution of crystal structural, magnetic, and electrical transport properties in the iridates Eu2Ir2−xRuxO7 (x = 0.0, 0.1, 0.3, and 0.5). Powder X-ray diffraction measurement indicates the prepared polycrystalline samples retain the cubic pyrochlore-type structure. The evolution of magnetism has been studied using dc magnetic susceptibilities. Although the magnetic irreversibility temperature changes marginally, the magnetic moment increases with progressive Ru doping. A distinct metal-insulator transition is observed for Eu2Ir2−xRuxO7 series. The nature of electronic conduction in the low temperature insulating state has been found to follow a power law behavior. Interestingly, we found the resistivity increases with Ru doping in Eu2Ir2−xRuxO7. The results may be ascribed to increased electronic correlation and Ir/Ru substitutional disorder, which interrupt direct Ir–Ir hopping in the samples.