Mössbauer effect at 119 Sn 4+ nuclei in fine crystalline MnO

The hyperfine structure of the low-temperature Mössbauer spectra of dopant 119 Sn 4+ ions (0.4 at. %) in a fine crystalline MnO sample, characterized by X-ray diffraction and magnetic measurements, has been studied. The 119 Sn spectra show that tin is distributed over positions with an inhomogeneous cationic environment. The appearance of such positions is explained by the local compensation for the excess charge of Sn 4+ by manganese vacancies V Mn and segregation of defects resulting in precipitation of MnSnO 3 clusters. The non-uniform distribution of Sn 4+ and the related dependence of the number of broken magnetic bonds on the local tin concentration are responsible for the fluctuation of the T N values, which is “perceived” by 119 Sn in different MnO crystallites. The 119 Sn spectra exclude the possibility that tin enters into the composition of superpara-magnetic particles.