Formation of Ti2AlC-based thin films via magnetron sputtering and annealing under vacuum

• Published in: Thin solid films 2021-11, Vol.737, p.138953, Article 138953
• Main Authors: Cherkasova, Nina, Ogneva, Tatyana, Burov, Vladimir, Sokolov, Ilya, Kuzmin, Ruslan, Khabirov, Roman
• Format: Article
• Language: English
• Subjects: Lamellar grains; MAX phases; Microstructure; Plate-shaped grains; Thin film; Titanium aluminum carbide; X-ray diffraction
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2021.138953

•A material consisting of 97.1% Ti2AlC and 2.9% TiC was obtained.•The material contained nanoscale hexagonal platelet structures.•The long sides of the platelets were oriented perpendicular to the Al2O3 substrates.•The coherent scattering region of Ti2AlC was approximately 64 nm in diametr. High-purity Ti, Al and C targets were used to fabricate Ti2AlC-based thin films on industrial polycrystalline Al2O3 substrates via magnetron sputtering under argon, followed by vacuum annealing. The phase compositions of the Ti2AlC-based thin films were analysed, and scanning electron microscopy was performed to investigate their structures. Grain size and morphology depended on the deposition pattern. A material composed of ∼97.1% Ti2AlC and ∼2.9% TiC was obtained by sputtering Al for thirty minutes, then sputtering four alternating layers of Ti and C for ten minutes each. The thin film was subsequently annealed under vacuum at 900°C for 60 minutes. The samples contained lamellar hexagonal plate-shaped grains structures. The plate-shaped grains ranged from 200 nm to 400 nm in length depending on the sputtering mode. The long sides of the lamellar grains were predominantly oriented perpendicular to the alumina substrates. Regardless of the sputtering conditions, the coherent scattering region of Ti2AlC was ∼64 nm in size after annealing at 900°C. Changes in the size of the coherent scattering region of the TiC phase were non-linear and ranged from 9 to 60 nm.