Oxygen diffusion at high temperatures within the SnO2/Sst interlayer in sputtered thin films

SnO2 and Stainless Steel 316 (Sst) films are useful materials for the production of interferential decorative coatings because they provide a high sputtering rate and low cost respectively. Multilayers of SnO2 and Stainless Steel 316 were deposited using DC pulsed magnetron sputtering, and oxygen diffusion processes were studied in the interface. Studies were made at selected temperatures between 450 °C and 650 °C for different exposure times: 0, 15, 30, 60 and 120 min. TOF-SIMS depth profiles determined the oxygen penetration in Sst films and evidenced the formation of a chromium oxide film. This method is noted for its simplicity for a full study at different temperatures and exposure times with few TOF-SIMS measurements. Oxidation kinetics can be described by two different contributions: a fast oxide film formation and parabolic growth. Results are useful for predicting the thickness of the chromium oxide film and the degradation of the coating at high temperatures.