Protective coating and method

A device comprising (i) a first layer having a first surface comprising a first metal; and (ii) a second layer comprising an oxide of a second metal bonding directly to the first surface of the first layer and covering at least a part of the first surface of the first layer, wherein: (A) the interface between the first layer and the second layer is substantially dense and has an irregular topography; and (B) the second metal is capable of forming an alloy with the first metal when the second metal is deposited on the first surface of the first metal at an elevated temperature. The device can be advantageously formed by a process including a step of forming a mixture such as an intermetallic of the first metal and the second metal over the first metal, followed by oxidation of the metal mixture at an elevated temperature.