Ceramic compositions useful for thermal barrier coatings having reduced thermal conductivity

A thermally protected article, which comprises:

• A. a metal substrate;
• and
• A. a thermal barrier coating comprising:
• 1. from about 92 to about 95 mole % zirconia;
• and
• 2. from about 5 to about 8 mole % of a stabilizer component comprising:
• a. a first metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof in amount of from about 3 to about 5 mole %;
• b. a second metal oxide of a trivalent metal atom selected from the group consisting of lanthana, and mixtures of lanthana with gadolinia, neodymia, samaria, or dysprosia, in an amount of from about 0.25 to about 2 mole %;
• and
• c. ytterbia in an amount of from about 0.5 to about 2 mole %.

A method for preparing a thermal barrier coating on an underlying metal substrate, the method comprising the step of:

• A. forming a thermal barrier coating over the metal substrate by depositing a ceramic composition, which comprises:
• 1. from about 92 to about 95 mole % zirconia;
• and
• 2. from about 5 to about 8 mole % of a stabilizer component comprising:
• a. a first metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof in amount of from about 3 to about 5 mole %;
• and
• b. a second metal oxide of a trivalent metal atom selected from the group consisting of lanthana, and mixtures of lanthana with gadolinia, neodymia, samaria, or dysprosia, in an amount of from about 0.25 to about 2 mole %;
• and
• c. ytterbia in an amount of from about 0.5 to about 2 mole %.