The crucial role of defect structure in understanding the electrical properties of spark plasma sintered antimony doped barium stannate

Abstract

The influence of structural defects in spark plasma sintered BaSn _1-x Sb _x O _3 (BSSO, x = 0.00 and 0.08) ceramic samples on their electrical properties was investigated in the temperature range of 300–4 K. X-ray photoelectron spectroscopy (XPS) revealed the presence of point defects, primarily oxygen vacancies (V _O ) and mixed oxidation states of tin (Sn ^2+ /Sn ^4+ ) in both samples. As a result, the undoped BSSO sample exibited a non-standard semiconductor behavior, retaining its temperature-dependent resistivity. The electrical resistivity of the doped samples was two orders of magnitude lower than that of the undoped sample. The presence of structural defects such as V _O , mixed oxidation states of the constituent elements, and significant amounts of O ^− species make the electrical resistivity of the doped sample constant in the temperature range of 300–70 K, indicating heavily-doped semiconductor behavior.

Keywords

• barium stannate
• spark plasma sintering
• point defects
• electrical resistivity
• x-ray photoelectron spectroscopy