Growth mechanism of thin films of yttria-stabilized zirconia by chemical vapor infiltration using NiO–ceria substrate as oxygen source

The deposition of yttria-stabilized zirconia films on a NiO–ceria substrate by chemical vapor infiltration (CVI) using ZrCl4 and YCl3 as metal sources and NiO–ceria as oxygen source was studied. The resultant films were cubic YSZ with a Y2O3 content of 3.7–4.2 mol%, and were transparent and strong. A NiO content of NiO–ceria above 60 mol% increases the growth rate of the YSZ film from about 5 to 25 μm over 2 h, indicating that chemical vapor deposition (CVD) occurred in addition to electrochemical vapor deposition (EVD), whereas NiO contents below 60 mol% does not affect the growth rate, indicating that only electrochemical vapor deposition occurred. The growth mechanism of the YSZ film is determined and a YSZ thin film is successfully fabricated on NiO–ceria to improve mechanical strength.