Electronic and Magnetic Properties of Pyrochlore (Eu(1-x)Dyx)2Ir2O7

Abstract

The pyrochlore (Eu(1-x)Dyx)2Ir2O7 for x = 0, 0.25, 0.50, 0.75, and 1.0 were prepared using solid-state reaction method. As the Dy concentration increases, the X-ray results indicate a systematic decrease of the cubic lattice parameter of (Eu(1-x)Dyx)2Ir2O7. We observed metal insulator transition in all compounds in addition two new anomalies at high temperatures in specifi c heat and resistivity results. The origin of these anoma- lies have not yet been identifi ed. The metal insulator transition temperature TMI of (Eu(1-x)Dyx)2Ir2O7 increases with the reduction in the lattice parameter. In the mag- netic susceptibility results, the effective magnetic moment increases with the increment of the Dy substitution for Eu ions. The magnetic fi eld dependence of resistivity was in- vestigated for all samples, negative and positive magnetoresistance effects are discussed.