Comprehensive review on lanthanum based thermal barrier coating materials for high temperature applications

Studies on thermal barrier coatings (TBC) are currently trending as the demand for thermal insulation is increasing day by day in harsh environments such as gas turbine thermal power plants, nuclear power plants, aerospace and aviation sectors, and other applications which involves high temperatures. As previous researches on using lanthanum based materials as an alternative to yttrium stabilised zirconia for thermal barrier coating applications implied that lanthanum shows a promising replacement to yttrium stabilised zirconia amongst all other ceramic materials, the primary aim of this comprehensive review is to study lanthanum oxide as a stabilising material to zirconium oxide for the formation of La2Zr2O7 (lanthanum zirconate, also called as LZ), which could hopefully be used as an ideal TBC material in the future. Moreover, this work elaborately explains the properties (physical, thermal, mechanical), synthesis methods, and characterisation techniques of the powder and summarises various efficient and effective coating techniques that could be used while performing thermal barrier coating. In conclusion to this review, future research directions of lanthanum-based TBC materials for use as TBCs are brought forward.