Al-C, Cr-C, Al-Cr and Al-Cr-C thin film coatings were sputtered onto Ni-201 substrates. Samples were deposited with 1.0 +/- 0.3 mg cm(-2) Na2SO4 and exposed to dry air/2 ppm SO2 gas atmosphere, at 700 degrees C for 250 hours. Coated samples had reduced corrosion rates relative to uncoated samples. Al-C and Cr-C coatings were not effective since NiO was the only compound detected on the surfaces; in contrast Cr-Al and Cr-Al-C developed protective layers of Al2O3 and Cr2O3 with Cr-Al-C coated samples having the least corrosion rate. (C) 2017 The Electrochemical Society. All rights reserved.