Patent ID: 7700508

Claim:
In a coating composition comprising: a base majority component selected from the group consisting of an oxide of zirconium, hafnium and combinations thereof; a first dopant oxide selected from the group consisting of an oxide of yttrium, dysprosium, erbium and combinations thereof; at least one small rare earth oxide selected from the group consisting of an oxide of ytterbium, holmium, lutetium, scandium, and combinations thereof; at least one large rare earth oxide selected from the group consisting of an oxide of neodymium, samarium, europium, gadolinium and combinations thereof; and at least one toughening oxide selected from the group consisting of an tetravalent oxide of titanium, and at least one toughening oxide selected from the group consisting of a pentavalent oxide of tantalum, niobium, and combinations thereof said composition forming a thin layer on a metal substrate.