title: Direct solvothermal synthesis of early transition metal nitrides.
abstract: Solvothermal reactions of TaCl5 with LiNH2 in benzene result in nanocrystalline Ta3N5 at 500 or 550 degrees C. The approximately 25 nm Ta3N5 particles have a band gap of 2.08-2.10 eV. The same reactions in mesitylene resulted in a higher crystallization temperature and large amounts of carbon incorporation due to solvent decomposition. Reactions of Ta(NMe2)5 with LiNH2 under the same conditions resulted in TaN. Rocksalt-type MN phases are obtained for Zr, Hf, or Nb when their chlorides (ZrCl4, HfCl4, or NbCl5) or dialkylamides (M(NEtMe)4, M = Zr, Hf) are reacted with LiNH2 under similar conditions. With the amides, there is some evidence for nitrogen-rich compositions (HfN >1), and carbon is incorporated into the products through pyrolysis of the dialkylamide groups.
authors.affiliation: School of Chemistry, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Baishakhi
authors.initials: B
authors.lastname: Mazumder
authors.forename: Pietro
authors.initials: P
authors.lastname: Chirico
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Hector