I am interested in coating the inside of a waveguide with a thin layer of niobium (columbium) for cryogenic microwave experiments. We think that electroplating may be the best way. Can this element be deposited from a plating solution? P. M.
Niobium cannot be deposited from aqueous solutions. Some early papers suggested that this could be done but apparently the process could not be repeated. Niobium has been deposited from fused molten fluorides in an argon atmosphere.
In the last number of years there has been many reports of using PVD (physical vapor deposition) or CVD (chemical vapor deposition) to deposit niobium on various substrates. A quick search on the Internet came up with a large number of references. A number of companies can perform this process commercially and can be found by searching the Internet.