**5.14. Electrophoretic deposition method**

Wang et al. [43] synthesized Gd2O3 doped 4-YSZ (G-YSZ) ceramic coatings by electrophoretic deposition method followed by vacuum sintering and isothermally annealing at 1,000°C for different times. XRD was used to investigate their phase composition. SEM was employed to examine their microstructure, while EDS was used to assess the composition of the composite coatings. The results showed that YSZ coating was composed of tetragonal and monoclinic phases after vacuum sintering at 1,000°C for 2 h under vacuum (<10−3 Pa). G-YSZ composite coatings were composed of tetragonal and monoclinic phases and a small amount of Gd2Zr2O7 phase after vacuum sintering at 1,000°C for 2 h while the content of the monoclinic phase in G-YSZ composite coatings increased with the increase of Gd2O3 concentration. It was found that after isothermal annealing at 1,000°C in air for 100 h, G-YSZ composite coatings were composed of tetragonal ZrO2 phase, monoclinic ZrO2 phase, and cubic phase whereas the Gd2Zr2O7 phase disappeared [44].
