Structural, Magnetic, and Electrical Properties of Bi2Ir2–xCuxO7 (0.0 ≤ x ≤ 0.5): A Mixed Valence Metallic Pyrochlore Iridate System

Abstract The present study investigates the crystal structure, electrical transport, and magnetic properties of polycrystalline Bi 2 Ir 2– x Cu x O 7 pyrochlore samples in the 0.0 ≤ x ≤ 0.5 range. The results of the magnetic susceptibility measurements of Bi 2 Ir 2– x Cu x O 7 ( x ≠ 0) indicate a notable divergence between the zero-field cooling (ZFC) and field cooling (FC) modes, which suggests the potential influence of magnetic frustration in the system. This behavior is consistent with previous reports on Bi 2 Ir 2 O 7 , where small negative Curie–Weiss temperatures ( θ ) were observed. The effective magnetic moment in the Cu-doped samples decreases with increasing Cu content, which can be attributed to a rise in the Ir 5+ species. Furthermore, the electrical resistivity of the system displays a metallic behavior, which is influenced by grain boundary effects and electron-electron scattering processes. These findings provide insight into the complex interplay between doping, magnetic behavior, and electronic transport in Bi 2 Ir 2– x Cu x O 7 . Graphical Abstract