RF-SPUTTERING OF CATALYTIC PTRH THIN-FILM ON CERAMIC SUBSTRATE

A new design of a ceramic catalyst support composed of several substrate components enables the use of rf-sputtering for depositing a PtRh alloy catalytic thin film. In the pre-treatment of the substrate a layer of γ-Al2O3 was deposited on each ceramic component by the wash-coat method. The base ceramic was cordierit and the wash coat enlarged its effective surface area. The catalytic PtRh film was then deposited by rf-sputtering in Ar at a pressure of 4 and 6 Pa in a diode system. The average film thickness measured on the polished substrate was 200 nm. The target electrode was composed of PtRh alloy with 10 wt% of Rh. Analytical results for freshly deposited thin films are presented with the use of energy dispersive X-ray (EPMA) and AES depth profile technique. © 1990.