Components with thermal barrier coatings having solid films thereon and methods of coating the same

A method, comprising:

• depositing a coating composition on a substrate, the coating composition comprising:
• from about 3 to about 50 wt. % of one or more rare-earth oxides;
• from about 45 to about 96.5 wt. % zirconia;
• and
• from about 0.5 to about 4 wt. % alumina, each based on the total weight of the coating composition;
• heat treating the substrate with the coating composition thereon to form a calcia-magnesia-alumina-silicate (CMAS)-resistant thermal barrier coating (TBC) on the substrate, wherein the CMAS-resistant TBC includes a columnar microstructure with voids in open communication with a surface thereof, wherein the alumina is deposited homogeneously throughout the CMAS-resistant TBC;
• contacting the CMAS-resistant TBC with a film precursor;
• transporting the film precursor along interior wall surfaces of the voids of the CMAS-resistant TBC to form a thin film thereon, wherein the thin film has a thickness on the interior wall surfaces of at least 10 nm and less than 150 nm;
• and
• forming a solid film on the interior wall surfaces of the voids from the film precursor, wherein the solid film includes aluminum phosphate, wherein the solid film does not completely fill at least some of the voids that have diameters of 50 nm or greater.