title: Titanium carbide, nitride and carbonitrides: a 13C, 14N, 15N and 47,49Ti solid-state nuclear magnetic resonance study.
abstract: The first 47,49Ti, 13C, 14N and 15N solid-state nuclear magnetic resonance (NMR) spectra of titanium carbide, nitride and a series of cubic carbonitrides have been obtained under both static and magic-angle spinning (MAS) conditions. The 15N samples were isotopically enriched by gas-solid exchange at 1000 degrees C in a closed system. The Ti spectra of the carbide and nitride are sharp, reflecting the well defined cubic symmetry of these compounds, but become considerably broadened in the carbonitride series, with the spectra being approximately the sum of TiC and TiN together with some small electric field gradient (EFG) effects. The resonance positions and widths of all the NMR spectra change as carbon is progressively replaced by nitrogen. A relationship is observed between the 13C chemical shift and the nitrogen content of the carbonitrides, suggesting a possible NMR method for estimating the composition of these compounds. Although electron paramagnetic resonance (EPR) spectra of all these compounds show typically metallic behaviour, the NMR spectra show few effects attributable to conduction electrons, probably due to the lack of s-orbital contributions to the conduction band.
authors.affiliation: New Zealand Institute for Industrial Research and Development, Lower Hutt.
authors.forename: K J
authors.initials: KJ
authors.lastname: MacKenzie
authors.forename: R H
authors.initials: RH
authors.lastname: Meinhold
authors.forename: D G
authors.initials: DG
authors.lastname: McGavin
authors.forename: J A
authors.initials: JA
authors.lastname: Ripmeester
authors.forename: I
authors.initials: I
authors.lastname: Moudrakovski
mesh_terms: D002247:Carbon Isotopes; D004578:Electron Spin Resonance Spectroscopy; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009584:Nitrogen; D009587:Nitrogen Isotopes; D014025:Titanium / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D007554:Isotopes; D009587:Nitrogen Isotopes; C096522:titanium carbonitride; C096521:titanium carbide; C041500:titanium nitride; D014025:Titanium; D009584:Nitrogen