title: Ammonium fluoride-activated synthesis of cubic δ-TaN nanoparticles at low temperatures.
abstract: Cubic delta-tantalum nitride (δ-TaN) nanoparticles were selectively prepared using a K2TaF7 + (5 + k) NaN3 + kNH4F reactive mixture (k being the number of moles of NH4F) via a combustion process under a nitrogen pressure of 2.0 MPa. The combustion temperature, when plotted as a function of the number of moles of NH4F used, was in the range of 850°C to 1,170°C. X-ray diffraction patterns revealed the formation of cubic δ-TaN nanoparticles at 850°C to 950°C when NH4F is used in an amount of 2.0 mol (or greater) in the combustion experiment. Phase pure cubic δ-TaN synthesized at k = 4 exhibited a specific surface area of 30.59 m2/g and grain size of 5 to 10 nm, as estimated from the transmission electron microscopy micrograph. The role of NH4F in the formation process of δ-TaN is discussed with regard to a hypothetical reaction mechanism.
authors.affiliation: Graduate School of Green Energy Technology, Chungnam National University, Daejeon 305-764, Republic of Korea. jonglee@cnu.ac.kr.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Lee
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Kap-Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Moon-Hee
authors.initials: MH
authors.lastname: Han
authors.forename: Kyoung-Soo
authors.initials: KS
authors.lastname: Kang
authors.forename: Ki-Kwang
authors.initials: KK
authors.lastname: Bae
authors.forename: Jong-Hyeon
authors.initials: JH
authors.lastname: Lee