Decomposition and Phase Transformation of Ti2AlN Max Thin Film Upon Annealing in Ultra-high-vacuum

• 作 者: HongmeiJin;
• 机 构: Institute of High Performance Computing
• 出 处: The 5th International Congress on Ceramics, ICC5(第五届国际陶瓷大会)
• 发表日期: 2014年期

　　Phase stability of single-crystalline Ti2AlN thin film in ultra high vacuum(UHV)has been studied in-situ by X-ray photoelectron spectroscopy(XPS)as a function of annealing temperature and ex-situ by atomic force microscopy(AFM),secondary ion mass spectroscopy(SIMS),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD)and nano-indentation.Ti2AlN is stable up to 600℃.At 700℃,Al is preferentially lost from the surface and becomes nearly undetected by XPS at 900℃,where single crystalline Ti2AlN with terrace morphology transforms into polycrystalline TiN1-x and TiN0.75-y phases with voids on the surface and reduced film thickness.Mechanical properties including hardness and Youngs modulus are weakened.Density function theory(DFT)calculation shows that Al atoms prefer to diffuse out from the Ti2AlN horizontally along the Al planes.