XANES Mn K edge in NaNbO3 based ceramics doped with Mn and Bi ions

Sodium niobate based ceramics doped with Mn atoms have been sintered from oxides. The Bi co-dopants were introduced to increase the solubility limit for Mn atoms. Two series of samples were heated at lowered air pressure to produce oxygen nonstoichiometry. X-ray Absorption Near Edge Structure (XANES) spectra at Mn K-edge were measured for samples with and without Bi co-dopants. Theoretical XANES spectra were calculated using the Real Space Multiple Scattering method (FEFF 8 code). The simulation showed that ceramics samples have Pbcm symmetry and all of them have Mn atoms located in a Nb sublattice.