Abstract: An amorphous thin film stack can include a first layer including a combination metals or metalloids including: 5 at % to in 90 at % of a metalloid; 5 at % to 90 at % of a first metal and a second metal independently selected from titanium, vanadium, chromium, iron, cobalt, nickel, niobium, molybdenum, ruthenium, rhodium, palladium, tantalum, tungsten, osmium, iridium, or platinum. The three elements may account for at least 70 at % of the amorphous thin film stack. The stack can further include a second layer formed on a surface of the first layer. The second layer can be an oxide layer, a nitride layer, or a combination thereof. The second layer can have an average thickness of 10 angstroms to 200 microns and a thickness variance no greater than 15% of the average thickness of the second layer.