Recently, nanostructured thermal barrier coatings, due to the extraordinary properties, have attracted much attention. This coating, due to better efficiency and lifetime compared to conventional coatings, has been developed. It was well known that conventional thermal barrier systems based on YSZ have two major problems, the hot corrosion resistance was low and have unstable phase at very high temperatures (over 1200 °C). Therefore, improving the hot corrosion resistance and thermal stability of YSZ systems, to develop applications, is a critical parameter. However, numerous efforts has been done to improve the hot corrosion resistance and thermal stability of thermal barrier coatings. Recently, using a combination of several stabilizers to achieve sustainable properties and better thermal barrier coatings life time has been considered by researchers. Research has shown that the microsized SYSZ plasma spray coatings, have more thermal stability and hot corrosion resistance than YSZ and ScSZ, but so far no research has been done on SYSZ nanocoating. In this research, SYSZ nanopowder was synthesized by the modified sol–gel method; then as-prepared nanopowder was agglomerated with spray drying method. The SYSZ nanostructured thermal barrier coatings was prepared by plasma spraying method and coating properties such as microstructure, adhesion strength, high temperature phase stability, thermal insulation capacity, thermal diffusitivity, hot corrosion and thermal shock resistance, were evaluated and compared with conventional YSZ coatings. Transmission electron microscopy images showed that the average SYSZ particle size was equal to 17±3 nm. The results showed that SYSZ nanocoating have better thermal iulation (?T=92 °C), high temperature phase stability (up to 1400 °C) and hot corrosion resistance (degradation time equal to 300 h) than conventional YSZ coating (?T=72 °C, T instability =1200 °C and t degradation =18 h, respectively). Thus, SYSZ nanocoating can be used as a promissing alternative thermal barrier coatings for gas turbine
