Valence state and magnetism of Mn-doped PbPdO2 nanograin film synthesized by sol-gel spin-coating method

•A sol-gel spin-coating method was developed for preparing Mn-doped PbPdO2 film.•The valence state of Mn ions within PbPdO2 lattice was clarified.•The obtained intrinsic ferromagnetism can be retained to above room temperature.•The magnetism was explained with a carrier-mediated mechanism bridged to BMP model.

The Mn-doped PbPdO2 nanograin film with many Pb vacancies was synthesized by using a sol-gel spin-coating method. The valence states for Pb, Pd and Mn ions were found to be 2 +, 2 + and the mixed one of 3 + and 4 +, respectively. The existence of Pb vacancies was believed to result in the increase of the Mn valence. The ferromagnetism and the antiferromagnetism were found to coexist in the formed Mn-doped PbPdO2 nanograin film. The ferromagnetism which can be maintained to above the room temperature was proved to be intrinsic. The carrier-mediated mechanism bridged to bound magnetic polaron model was used to explain the coexistence of the antiferromagnetism and the ferromagnetism within the Mn-doped PbPdO2 film.