The growth of a multi-principal element (CoCrFeMnNi) oxynitride film by direct current magnetron sputtering using air as reactive gas

• Published in: Surface & coatings technology Vol. 421; p. 127433
• Main Authors: Radnóczi, G., Dedoncker, R., Radnóczi, G.Z., Czigány, Zs, Sulyok, A., Kovács-Kis, V., Depla, D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.09.2021; Elsevier BV
• Subjects: Alloying elements; Argon; CoCrFeMnNi MPEA; Crystal structure; Direct current; FCC metals; Film growth; Growth in Ar + air plasma; Magnetron sputtering; MPEA-oxynitride; Nitrogen; Nucleation; Preferred orientation; Spinodal decomposition; Stochastic structure; Structure formation mechanism; Stochastic structure; Structure formation mechanism; CoCrFeMnNi MPEA; Growth in Ar + air plasma; MPEA-oxynitride; Spinodal decomposition
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2021.127433

CoCrFeMnNi multi-principal element alloy films were grown by direct current magnetron sputtering in a mixture of argon and air. The air fraction was varied from 4 to 50%, which resulted in a change of the phase state of the growing film. A 〈100〉 preferred orientation face centered cubic metal (doped with O and N) structure develops below 12% of air. Between 12 and 30% air, a two phase 〈100〉 preferred orientation face centered cubic metal + oxynitride (B1) structure forms. Above 30% of air a single phase B1 oxynitride structure is observed. Compared to nitrogen, oxygen is preferentially incorporated into the growing structures. The 〈100〉 preferential orientation is the result of selective nucleation (below 30% of air) or competing growth (above 30% of air) of the forming crystals. Detailed microscopic analysis shows a complex structure for both the metal and the oxynitride phase in the films deposited at low and high air fraction. In both cases, the films are characterized by local structures ordered on a few nanometer scale and their formation is explained as a result of spinodal decomposition of the as-formed homogenous structure which occurs during film growth. [Display omitted] •CoCrFeMnNi alloy films were grown by direct current magnetron sputtering in a mixture of argon and air.•The air fraction was varied from 4 to 50 %.•The structure changes from fcc metallic to a B1 type oxynitride phase between 20 % and 30 % air in sputtering gas.•Oxygen is preferentially incorporated compared to nitrogen into the growing structures.•The stochastic and defective nano-structures are the result of spinodal processes taking place during the growth process.