Platinum Metals Rev., 1966, 10, (1), 13
The Vapour Phase Deposition of Rhodium
Interest in the vapour phase deposition of the platinum metals has been hindered by the difficulty of establishing the most suitable volatile compounds of these metals on which to base a reliable process. For applications where electrodeposition or other methods of coating cannot be employed, or can be used only with considerable difficulty, a vapour phase technique would present considerable potentialities, and a paper by Hemert, Spendlove and Sievers (J. Electrochem. Soc., 1965, 112, (11), 1123) is of value in this connection.
These workers found that certain fluor-carbon-β-diketonate metal chelates are not only highly volatile but are thermally stable and are readily reduced to metal at atmospheric pressure at temperatures as low as 250°C.
Thin films of copper, nickel and rhodium were produced in a simple apparatus in which two different temperatures could be maintained simultaneously in different sections. The gaseous chelate was transported by a stream of hydrogen to the reduction zone, where it was reduced to metal.
The deposits obtained adhered very well to the glass tubes on which they were formed, even though the tubes had not been specially cleaned or etched. They were all mirror-like on both surfaces, and all were electrically conductive. They were ductile and when scraped from the substrate could be folded without fracture.