High-Pressure Synthesis and Magnetic and Electrical Properties of Fe-Doped Bi₃Re₃O₁₁ and Bi₃Os₃O₁₁

Under high-pressure and high-temperature conditions, doped Bi₃Re₃O₁₁ and Bi₃Os₃O₁₁ with Fe up to 29 atomic % were synthesized. The crystal structures and chemical compositions of Bi₃Os_2.45Fe_0.55O₁₁ and Bi₃Re_2.13Fe_0.87O₁₁ were determined by synchrotron powder X-ray diffraction and electron probe microanalysis. Both crystal structures were explained by a KSbO₃-type model with the space group Pn3̅. Magnetic and electronic transport property measurements showed that Bi₃Os_2.45Fe_0.55O₁₁ exhibited a ferrimagnetic transition at the highest magnetic ordering temperature of 490 K in the KSbO₃-type, while Bi₃Re_2.13Fe_0.87O₁₁ exhibited a spin glassy behavior below 22 K. The magnetoresistance at 5 K and 90 kOe was almost zero for Bi₃Os_2.45Fe_0.55O₁₁, but -10% for Bi₃Re_2.13Fe_0.87O₁₁. These results suggest that KSbO₃- type 5d oxides, which exhibit only weak temperature-dependent paramagnetism to date, are a group of compounds that can be converted into spintronic materials by doping with 3d elements, leading to the development of new KSbO₃-type materials with both theoretical and practical significance.