Self-passivating (Re, Al)B2 coatings synthesized by magnetron sputtering. Issue 1 (December 2018) - Bliem, Pascal
Abstract (Re0.67 Al0.10 )B2 and (Re0.74 Al0.11 )B2 solid solution as well as Re0.85 B2 thin films were deposited by hybrid RF-DC magnetron sputtering. X-ray diffraction (XRD) showed that all films exhibit the ReB2 (P6 3 /mmc ) crystal structure. X-ray photoelectron spectroscopy (XPS) analyses performed on atmosphere exposed thin film surfaces suggest that ReB2 corrodes, consistent with literature, by forming perrhenic acid (HReO4 ) already after two days, while (Re0.74 Al0.11 )B2 forms a self-passivating Al-oxide layer preventing corrosion in a time period ≥ 60 days. Hence, it is evident that Al additions to ReB2 significantly increase the chemical stability during atmosphere exposure.