engleski

Structural Studies of Nanocrystalline Antimony-Doped Tin Oxide (ATO) from RT to 550 &ordm ; C

Nanocrystalline antimony-doped tin oxide (ATO) samples with doping level up to 14 at% Sb were hydrothermally prepared and characterized by X-ray powder diffraction, as well with ^(121)Sb Mössbauer spectroscopy. Diffraction lines were broadened, the line broadening being anisotropic. The Sb-doping level influenced both the line broadening and the line widths anisotropy. All samples were isostructural with TiO_2 (rutile). Unit-cell parameters increased with Sb content. Crystal structure indicated that both Sb^(3+) and Sb^(5+) were substituted for Sn^(4+) in the SnO_2 structure, Sb^(3+) being dominant for the as-prepared samples. Mössbauer spectroscopy confirmed the XRD results. The sample with 6.2 at% Sb was additionally annealed at 350, 450 and 550 &ordm ; C for 1 h. Broadening of diffraction lines increased due to annealing at 350 &ordm ; C, then decreased upon further heating. The line anisotropy decreased over the whole temperature range. Unit-cell parameters of the annealed sample decreased with the increase in thermal treatment temperature, which suggested that oxidation of Sb^(3+) took place in annealing process. Mössbauer spectroscopy showed that Sb^(3+)/Sb^(5+) content ratio decreased upon annealing.

Sb-doped tin oxide; X-ray diffraction; Mössbauer spectroscopy

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