The Microstructure of Nanocrystalline TiB2 Films Prepared by Chemical Vapor Deposition

• Main Authors: Xiaoxiao Huang, Shuchen Sun, Ganfeng Tu, Shuaidan Lu, Kuanhe Li, Xiaoping Zhu
• Format: Article
• Language: English
• Published: MDPI AG 2017-12-01
• Series: Materials
• Subjects: TiB2; nanocrystalline films; microstructure; chemical vapor deposition
• Online Access: https://www.mdpi.com/1996-1944/10/12/1425

Nanocrystalline titanium diboride (TiB2) ceramics films were prepared on a high purity graphite substrate via chemical vapor deposition (CVD). The substrate was synthesized by a gas mixture of TiCl4, BCl3, and H2 under 1000 °C and 10 Pa. Properties and microstructures of TiB2 films were also examined. The as-deposited TiB2 films had a nano-sized grain structure and the grain size was around 60 nm, which was determined by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Further research found that a gas flow ratio of TiCl4/BCl3 had an influence on the film properties and microstructures. The analyzed results illustrated that the grain size of the TiB2 film obtained with a TiCl4/BCl3 gas flow ratio of 1, was larger than the grain size of the as-prepared TiB2 film prepared with a stoichiometric TiCl4/BCl3 gas flow ratio of 0.5. In addition, the films deposited faster at excessive TiCl4. However, under the condition of different TiCl4/BCl3 gas flow ratios, all of the as-prepared TiB2 films have a preferential orientation growth in the (100) direction.