Magnetic and Electrical Behavior of Gd Doping Pyrochlore Bi₂Ir₂O₇

Gd-doped Bi₂Ir₂O₇ on the Bi site have been synthesized through solid-state method. The X-ray diffraction and the energy dispersive X-ray spectrometry show the formation of impurity-free polycrystals with cubic structure belonging to the space group Fd-3m. The Raman scattering measurement shows redshift and blueshift of active modes. The resistivity is measured by four-probe method. The resistivity measurement shows for x ≤ 1.5, the samples are metals and for x = 2.0, the sample changes to an insulator. The DC magnetization shows the enhancement of antiferromagnetism with doping. The micromagnetic structure of samples is studied by electron paramagnetic resonance. The electron paramagnetic resonance shows generally consistent behavior of major parameters (the absorption peak, g factor, linewidth, normalized intensity) at low temperature. All the parameters show strong dependence on temperature. The results show that the microscopic and macroscopic properties are consistent.