Plasma sprayed Yttria Stabilized Zirconia (YSZ) coatings have attracted the research community due to its good thermal, mechanical and tribological properties. Plasma-sprayed YSZ coatings with tetragonal prime (t') structure is one of the most commonly used thermal barrier coatings (TBC) because of its low thermal conductivity and phase stability at operating temperatures below 1200°C. However to increase the efficiency of TBCs, there is a need to develop materials with high temperature stability for long periods as well as lower thermal conductivity. This calls for designing a material with stable microstructure. This book reveals combined effect of nanostructure and doping of rare earth oxides on microstructure, mechanical, thermal and tribological properties of plasma sprayed YSZ coatings. An attempt is made to provide a comprehensive insight of the microstructure, thermo-mechanical, phase stability and wear behavior of recently developed nanostructured YSZ coatings doped withLanthanum-Cerium Oxide. Nanostructured Thermal Barrier Coatings will continue to be an important area of concern in coming years and this study is a small step in this direction.