Ceramic compositions useful for thermal barrier coatings having reduced thermal conductivity

A thermally protected article, which comprises:

• A. a metal substrate;
• and
• B. a thermal barrier coating comprising:
• 1. at least about 91 mole % zirconia;
• and
• 2. a stabilizing amount up to about 9 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;
• 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;
• and
• c. a third metal oxide of a trivalent metal atom selected from the group consisting of ytterbia, erbia and mixtures thereof.

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. at least about 91 mole % zirconia;
• and
• 2. a stabilizing amount up to about 9 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;
• 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;
• and
• c. a third metal oxide of a trivalent metal atom selected from the group consisting of ytterbia, erbia and mixtures thereof.