Microstructure and magnetism of sol-gel synthesized Co-doped PbPdO₂ nanograin film

The single-phase body-centered-orthorhombic-structured Co-doped PbPdO₂ thin film was obtained using the sol-gel spin-coating method and an oxidation treatment. The film had a nanograin microstructure with an average grain size of about 56 nm and a thickness of about 150 nm. The adoption of a moderate calcination temperature of 650°C was found to be very important for preparing the single-phase-PbPdO₂-based film with a high crystalline quality. The magnetic studies exhibited that the ferromagnetism and the paramagnetism coexist within the formed Co-doped PbPdO₂ film and the ferromagnetism can be maintained above room temperature. The saturation magnetization of the ferromagnetism increasing with the temperature, as the peculiar characteristic of the spin gapless semiconductor, was found within the film. The investigation on the film's X-ray absorption near-edge structure revealed that the ferromagnetism of the Co-doped PbPdO₂ is intrinsic.