The invention relates to a barrier layer provided on the electrode assembly of a discharge lamp comprising at least a layer of nanoclusters of a non-oxidizing material. Further, the invention relates to an electrode assembly for a discharge lamp comprising an electrode having a foil attached thereto to create an electrode assembly, the assembly being coated with a multi-layer coating comprising at least a layer of non-oxidizing material in the form of nanoclusters, and at least another layer of non-oxidizing material, such that the total coating thickness is up to 1500 nm. A method to reduce thermal expansion mismatch between an electrode assembly and a discharge lamp envelope is also provided, the method comprising providing an electrode assembly and depositing on the surface of the assembly a coating having at least a nanocluster layer of a non-oxidizing material, and subsequently subjecting the lamp envelope in the electrode assembly area to pinching to create a pinch area, this lamp being able to operate at elevated temperature for extended periods, in excess of 1000 hours.