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Free keywords:
Gallium tin zinc oxides; Transparent conducting oxides; Crystal structures; Transmission electron microscopy
Abstract:
Several members of hitherto unknown homologous compounds [Sn0.5Zn0.5]GaO3(ZnO)(m) (m=3-7) of the general formula ARO(3)(ZnO)(m) were prepared by solid state methods from the binary oxides in sealed Pt-tubes. UV-vis measurements confirm these compounds to be transparent oxides with an optical band gap in the UV region with E-g approximate to 3 eV. Rietveld refinements on powder samples of [Sn0.5Zn0.5]GaO3(ZnO)(m) proved the compounds to be isostructural with InGaO3(ZnO)(m) where In3+ on octahedral sites is replaced statistically by Sn4+ and Zn2+ in equal amounts preserving an average charge of 3+. Additionally, the structure of [Sn0.5Zn0.5]GaO3(ZnO)(3) has been determined from flux-grown single crystals by X-ray diffraction (R (3) over barm, Z=3, alpha=3.2387(7) angstrom, c=41.78(1) angstrom, 19 parameters, 201 independent reflections, R1=0.047, omega R2=0.074). The compound [Sn0.5Zn0.5]GaO3(ZnO)(3) is isostructural with InGaO3(ZnO)(3). [Sn0.5Zn0.5]GaO3(ZnO)(3) was furthermore analyzed by High Angle Annular Dark Field (HAADF) scanning TEM and EELS spectroscopic imaging, supporting the structure model derived from X-ray diffraction data.
