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Gold coating a temperature sensitive material

Q. Hi,

I'm a physics graduate student, and as part of an experiment we would like to use this material called ammonia ⇦ this on eBay or Amazon [affil links] borane. There are two main issues with the substance. One is that it is quite hygroscopic (absorbs water pretty readily from the atmosphere), so we need some sort of vapor barrier. We think this can be accomplished with a parylene coating (ideal because we only want a thin, light coating). The other thing is that we need for it to have a conductive layer. Typically, we use sputter deposition to gold coat things (with a titanium layer first for adhesion). However, ammonia borane decomposes releasing hydrogen at as low as 70 °C. We are concerned that the sputter deposition may cause the substrate, that is the parylene-coated ammonia borane, to get too hot and start decomposing. Are there any other methods we could use to put a thin layer of gold on parylene without heating the substance?

Thanks

John Lee
student - Seattle, Washington, USA
September 21, 2012