Discovery of Ternary Silicon Titanium Nitride with Spinel-Type Structure

• Published in: Scientific reports Vol. 10; no. 1; p. 7372
• Main Authors: Bhat, Shrikant, Lale, Abhijeet, Bernard, Samuel, Zhang, Wei, Ishikawa, Ryo, Haseen, Shariq, Kroll, Peter, Wiehl, Leonore, Farla, Robert, Katsura, Tomoo, Ikuhara, Yuichi, Riedel, Ralf
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.04.2020; Nature Publishing Group
• Subjects: 639/301; 639/301/119; 639/638/263/915; 639/638/298; Chemical Sciences; Crystal structure; Crystals; High temperature; Humanities and Social Sciences; Material chemistry; multidisciplinary; Oxidation; Pressure; Science; Science (multidisciplinary); Silicon; Silicon nitride; Titanium
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-64101-5

Here we report on the discovery of a ternary silicon titanium nitride with the general composition (Si 1−x ,Ti x ) 3 N 4 with x = 0 < x < 1 and spinel-type crystal structure. The novel nitride is formed from an amorphous silicon titanium nitride (SiTiN) precursor under high-pressure/high-temperature conditions in a large volume high-pressure device. Under the conditions of 15–20 GPa and 1800–2000 °C, spinel-type γ-Si 3 N 4 and rock salt-type c-TiN are formed. In addition, crystals of the discovered nano-sized ternary phase (Si 1−x ,Ti x ) 3 N 4 embedded in γ-Si 3 N 4 are identified. The ternary compound is formed due to kinetically-controlled synthesis conditions and is analyzed to exhibit the spinel-type structure with ca. 8 atom% of Ti. The Ti atoms occur in both Ti 3+ and Ti 4+ oxidation states and are located on the Si sites. The ternary nano-crystals have to be described as (Si,Ti) 3 N 4 with N-vacancies resulting in the general composition (Si 4+ 1−x Ti 4+ x-δ Ti 3+ δ ) 3 N 4-δ .