Fabrication and properties of CaZr0.9In0.1O3−δ prepared by an auto-ignition combustion process

One of the major challenges in developing proton conducting CaZr0.9In0.1O3−δ is to achieve a high densification at low sintering temperature. In this work, an auto-ignition combustion process was first used to synthesize CaZr0.9In0.1O3−δ powders aiming to improve its sinterability. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and dilatometry measurement. The results indicate that a calcination temperature of 1000 °C is sufficient to form the CaZr0.9In0.1O3−δ phase. The as-obtained powders are fine, homogeneous and well crystallized, which strongly improves the sintering properties. Dense CaZr0.9In0.1O3−δ ceramics with uniform grain size were obtained by sintering at 1350 °C, which is much lower than that required for the conventional solid state reaction method. In addition, the electrical properties of CaZr0.9In0.1O3−δ ceramics were studied by electrochemical impedance spectroscopy.