Short Communication Structural study and proton conductivity in BaCe 0.7 Zr 0.25¡x Y x Zn 0.05 O 3 (x ¼ 0.05, 0.1, 0.15, 0.2 & 0.25) Ahmed Afif a,* , Nikdalila Radenahmad a , Chee Ming Lim b , Mohamad Iskandar Petra a , Md. Aminul Islam c , Seikh Mohammad Habibur Rahman d , Sten Eriksson d , Abul Kalam Azad a a Universiti Brunei Darussalam, Faculty of Integrated Technologies, Jalan Tunku Link, Gadong BE1410, Brunei Darussalam b Universiti Brunei Darussalam, Center for Advanced Materials and Energy Sciences, Jalan Tunku Link, Gadong BE1410, Brunei Darussalam c Universiti Brunei Darussalam, Faculty of Sciences, Jalan Tunku Link, Gadong BE1410, Brunei Darussalam d Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Goteborg SE 41296, Sweden article info Article history: Received 30 September 2015 Received in revised form 20 February 2016 Accepted 22 February 2016 Available online xxx Keywords: Proton conductor Sinterability Rietveld refinement Conductivity SOFC electrolyte abstract Solid oxide fuel cell (SOFC) has been considered to generate power represented by con- ductivity. Zinc doped Barium Cerium Zirconium Yttrium oxide (BCZYZn) has been found to offer high protonic conductivity and high stability as being electrolyte for proton- conducting SOFCs. In this study, we report a new series of proton conducting materials, BaCe 0.7 Zr 0.25x Y x Zn 0.05 O 3 (x ¼ 0.05, 0.1, 0.15, 0.2 and 0.25). The materials were synthesized by solid state reaction route and characterized by X-ray diffraction (XRD), scanning elec- tron microscopy (SEM), thermal expansion, particle size and impedance spectroscopy (IS). Rietveld analysis of the XRD data reveal a cubic perovskite structure with Pm-3m space group up to composition x ¼ 0.15. For x ¼ 0.15 and 0.20, the materials have structural phase change to orthorhombic in the Pbnm space group. Scanning electron microscopy images show high density materials. Thermal expansion measurements show that the thermal expansion coefficient is in the range 10.0e11.0  10 6 /  C. Impedance spectroscopy shows higher ionic conduction under wet condition compared to dry condition. Y content of 25% (BCZYZn25) exhibits highest conductivity of 1.84  10 2 S/cm in wet Argon. This study indicated that perovskite electrolyte BCZYZn is promising material for the next generation of intermediate temperature solid oxide fuel cells (IT-SOFCs). Copyright © 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: þ673 8953255. E-mail address: 14m0506@ubd.edu.bn (A. Afif). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2016) 1 e9 http://dx.doi.org/10.1016/j.ijhydene.2016.02.135 0360-3199/Copyright © 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Afif A, et al., Structural study and proton conductivity in BaCe 0.7 Zr 0.25x Y x Zn 0.05 O 3 (x ¼ 0.05, 0.1, 0.15, 0.2 & 0.25), International Journal of Hydrogen Energy (2016), http://dx.doi.org/10.1016/j.ijhydene.2016.02.135