title: Pulsed-laser deposited transition-metal carbides for field-emission cathode coatings.
abstract: Thin films of transition-metal carbides ZrC, HfC, and TiC were deposited by pulsed-laser deposition under vacuum. The surface chemistry of the films was characterized with ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy in situ. X-ray diffraction was used to characterize the film structure. TiC was shown to be nearly stoichiometric and polycrystalline. The TiC was applied to a vertically aligned carbon nanotube sample and characterized by field emission. Field-emission results showed enhanced current and current density at a film thickness, 5 nm, not previously reported in the literature. Emission from TiC films was also shown to be less affected by adsorbates during field emission. Pulsed-laser deposition of TiC offers a distinct advantage over other techniques in that high-quality films can be obtained under ultrahigh vacuum conditions without the use of a reactive background gas or excessively high annealing temperatures. The application of TiC by pulsed-laser deposition as a cathode coating shows potential for integration into a fabrication process.
authors.affiliation: Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base , 3005 Hobson Way, Ohio 45433, United States.
authors.forename: Tyson
authors.initials: T
authors.lastname: Back
authors.forename: Steven B
authors.initials: SB
authors.lastname: Fairchild
authors.forename: Kent
authors.initials: K
authors.lastname: Averett
authors.forename: Benji
authors.initials: B
authors.lastname: Maruyama
authors.forename: Neal
authors.initials: N
authors.lastname: Pierce
authors.forename: Marc
authors.initials: M
authors.lastname: Cahay
authors.forename: P Terrence
authors.initials: PT
authors.lastname: Murray