Characterization of scrutinyite SnO₂ and investigation of the transformation with ¹¹⁹Sn NMR and complex impedance method

Scrutinyite SnO2 was synthesized by annealing SnO nanoparticles fabricated from micron-size SnO via ball milling. The isotropic as well as anisotropic chemical shifts of 119Sn obtained by solid-state nuclear magnetic resonance method, were verified computationally using a pseudopotential method in density-functional theory. The results fit with 6-fold coordinated Sn. A linear relationship holds empirically between isotropic shift and coordination number divided by Sn-O average bond length in all polymorphs of tin oxides. When the annealing proceeded in an oxygen-free atmosphere, metallic tin, the rutile phase of SnO2 and oxygen vacancies associated with permanent electric dipoles were also detected by thermal analysis and dielectric spectroscopy.