Structural, thermal, electrical and morphological characterization of (Bi2O3)1−x−y(Sm2O3)x(Yb2O3)y nanostructures prepared by solid state synthesis

• Published in: Current applied physics 2016-12, Vol.16 (12), p.1588-1596
• Main Authors: Polat, Yasin, Dağdemir, Yılmaz, Arı, Mehmet
• Format: Article
• Language: English
• Subjects: Ceramics; Chemical synthesis; Electrical conductivity; Nanostructures; Oxides
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2016.09.013

In the present work, the ternary system of (Bi2O3)1−x−y(Sm2O3)x(Yb2O3)y was investigated. For the production and stabilization of the fcc-type solid solution, nano-Sm2O3 and nano-Yb2O3 were doped into nano-Bi2O3 by solid-state synthesis techniques. The XRD results showed that the crystallographic structure of the samples had displayed a fluorite type face-centered cubic δ-Bi2O3 phase. The phase stability was also checked by the DTA measurements. The temperature dependent electrical conductivity results revealed that the maximum electrical conductivity observed for the sample of the nanostructure-(Bi2O3)0.8(Sm2O3)0.1(Yb2O3)0.1 system was 5.39 × 10−2 (ohm.cm)−1 at 650 °C. The results also show that the lowest activation energy was 0.7062 eV and the lowest crystallite size was 31.62 nm for the nanostructure-(Bi2O3)0.75(Sm2O3)0.1(Yb2O3)0.15 system. Consequently, the face-centered cubic stable δ-phase-(Bi2O3)0.8(Sm2O3)0.1(Yb2O3)0.1 is the optimal dopant amount due to the relatively good stability and oxygen ionic conductivity obtained, which are two of our major concerns for the electrolyte layer of solid oxide fuel cells (SOFCs). TG/DTA curves of sample before (a) and after (b) electrical conductivity measurement nanostructure-(Bi2O3)0.7(Sm2O3)0.1(Yb2O3)0.2. [Display omitted] •(Bi2O3)0.8(Sm2O3)0.1(Yb2O3)0.1 conductivity is 5.39 × 10−2 (ohm cm)−1 at 650 °C.•SEM micrographs indicate the grains, boundary of grains with surface roughness.•All of the nanostructured samples relatively good stability and ion conductivity.•Due to ion conductivity and stability, samples can be used as electrolyte in SOFC.