Sintering resistant, low conductivity, high stability thermal barrier coating/environmental barrier coating system for a ceramic-matrix composite (CMC) article to improve high temperature capability

A method for producing a thermal barrier coating/environmental barrier coating system on a silicon containing material substrate comprising:

• applying an environmental barrier coating (EBC) over said silicon containing material substrate;
• and
• applying a thermal barrier coating (TBC) over the EBC, said thermal barrier coating comprising a compound having a primary constituent portion and a stabilizer portion stabilizing said primary constituent, said primary constituent portion of said thermal barrier coating consisting of a mixture of hafnia present in an amount of at least about 5 mol % of the primary constituent and zirconia, and said stabilizer portion of said thermal barrier coating comprises at least one metal oxide comprised of cations with a +2 or +3 valence present in the amount of about 10 to about 40 mol % of the thermal barrier coating, wherein the TBC compound has a cubic or a pycholore crystal structure.