Thermal barrier coating having high phase stability

A method for producing a device operable over a range of temperatures, the method comprising the steps of:

• providing a substrate;
• and
• depositing a first ceramic thermal barrier layer over the substrate;
• depositing a second ceramic thermal barrier layer over the first thermal barrier layer, the second ceramic thermal barrier layer comprising a chemical formula consisting essentially of An+2−xBm+2+xO7−y, where A is selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and mixtures thereof, where B is selected from the group consisting of Zr, Hf, Ti and mixtures thereof, n and m are the valence of A and B respectively, and where for −0.5≦x≦0.5, y = 7 - [ ( 2 - x ) ⁢ n + ( 2 + x ) ⁢ m ] 2 ,
• and excluding the following combinations for x=0, y=0:
• A=La and B=Zr, A=La and B=Hf, A=Gd and B=Hf, and A=Yb and B=Ti.

A thermal barrier coating composition capable of being applied to a substrate operating over a range of temperatures, the thermal barrier coating composition comprising:

• a first ceramic thermal barrier layer;
• and
• a second ceramic thermal barrier layer operatively engaged with the first ceramic thermal barrier layer and having a chemical formula comprising An+2−xBm+2+xO7−y, where A is selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and mixtures thereof, where B is selected from the group consisting of Zr, Hf, Ti and mixtures thereof, where n and m are the valence of A and B respectively, and where for −0.5≦x≦0.5, y = 7 - [ ( 2 - x ) ⁢ n + ( 2 + x ) ⁢ m ] 2 ,
• and excluding the following combinations for x=0, y=0:
• A=La and B=Zr, A=La and B=Hf, A=Gd and B=Hf, and A=Yb and B=Ti.