CaZrO₃ based materials have already been extensively applied as refractories, luminescent materials, as well as ferroelectric ones due to their physical and chemical stability, mechanical strength and excellent fluorescent and dielectric properties. Since the discovery of stable proton conductivity at a relatively high temperature by Iwahara in 1991, much progresses on CaZrO₃ based materials have been made during the past 20 years. This paper intends to review the progresses, as well as some researches of our group in this field, including powder synthesis method,ceramic sintering process,proton transfer mechanism and the major factors influencing proton conductivity. The problems and further orientation in this research area are also discussed. Contents 1 Introduction
2 Powder synthesis method
2.1 Solid-state reaction method
2.2 Co-precipitation method
2.3 Sol-gel method
2.4 Molten salt method
2.5 Hydrothermal method
2.6 High-energy ball milling method (mechanical activation method)
2.7 Auto-ignition method
2.8 Optimized solid-state reaction method
2.9 Gel-precipitation method
3 Ceramic molding and sintering process
3.1 Traditional ceramic molding and sintering method
3.2 Spin-coating method
3.3 Pulsed laser deposition method
4 Proton transfer mechanism
5 Major factors influencing proton conductivity
5.1 Dopants and dopant concentration
5.2 Temperature
5.3 Gas partial pressure
5.4 Gas flow rate
5.5 Atmosphere
5.6 Grain boundary
6 Conclusion and outlook