Microstructure and Electrical Conductivity of ZnO Addition on the Properties of (Bi0.92Ho0.03Er0.05)2O3

Ermiş I.; Çorumlu V.; Sertkol M.; Öztürk M.; Kaleli M.; Çetin A.; Turemiş M.; Arı M.

Microstructure and Electrical Conductivity of ZnO Addition on the Properties of (Bi0.92Ho0.03Er0.05)2O3

Date

2016

Authors

Publisher

Springer New York LLC

Abstract

The solid electrolyte is one of the most important components for a solid oxide fuel cell (SOFC). The various divalent or trivalent metal ion-doped bismuth-based materials exhibit good ionic conductivity. Therefore, these materials are used as electrolytes in the SOFC. In this paper, the samples of (Bi0.92−xHo0.03Er0.05)2O3 + (ZnO)x solutions with a 0 ≤ x ≤ 0.2 molar ratio are synthesized by the solid state reaction method. The detailed structural and electrical characterizations are investigated by using x-ray diffraction (XRD), alternating current electrochemical impedance spectroscopy, and scanning electron microscopy (SEM). The XRD patterns of all samples are indexed on a monoclinic symmetry with a P21/c space group. In addition, the rietveld parameters are determined by using the FullProf software program. The impedance measurements of the samples are obtained at the 1 Hz to 20 MHz frequency range. The impedance value of the pellets increases with temperature. Based on the impedance results, it is found that the contribution of grain (bulk) is more than a grain boundary in terms of conductivity, which permits the attribution of a grain boundary. The ionic conductivity decreases with an increasing amount of Zn contribution. The value of highest electrical conductivity among all samples is calculated as 0.358 S cm−1 at 800°C for undoped (Bi0.92Ho0.03Er0.05)2O3. © 2016, The Minerals, Metals & Materials Society.