Metastable phase formation of (Mo,Cr)2AlB2 MAB phase thin films revealed by theory and experiments

Abstract

A (Mo0.24Cr0.76)0.40Al0.32B0.28 thin film was deposited by direct current magnetron sputtering at 600 °C substrate temperature. Analysis by X-ray diffraction, energy-dispersive X-ray spectroscopy, elastic recoil detection analysis, and high-resolution scanning transmission electron microscopy revealed the formation of the previously unreported (Mo,Cr)2AlB2 MAB phase, along with Cr3AlB4, CrB4, and Mo, in good agreement with density functional theory (DFT) calculations. Hence, the MAB phase family in the Mo-Cr-Al-B system is extended by a novel, quaternary member.

Keywords

• MAB phase
• density functional theory
• magnetron sputtering
• phase formation
• thin film