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Fabrication of carbon nanotube cold cathode requires an efficient and low cost process. In the paper, carbon nanotube is direct synthesized on stainless steel which acts as cathode substrate and catalyst for growing carbon nanotube. The best type of stainless steel is chosen and investigated its effect on the synthesis quality of carbon nanotube. The field emission character of carbon nanotube on...
A good quality graphene is transferred onto honeycomb-like CNTs arrays with inner supporting CNTs. The efficient field emission is demonstrated due to a high aspect ratio protrusions and graphene crack edges. A high efficient current density about 1.2 mA/cm2 at threshold electric field of 7.8 V/μm with a turn-on electric field of 1.8 V/μm at the current density of 10 μA/cm2 is observed due to high...
Electric fields at metal-dielectric contact were calculated analytically and numerically. The obtained field exhibited enhancements strong enough to cause breakdown at a triple junction and more apparently at a quadruple junction. Such field enhancements may lead to a noble type of cold cathode.
This paper presents theory and analysis of single-tip field emission and electron beam propagation in the electrostatic focusing fields. It is shown that two gate apertures with a focusing anode allow transport of narrow electron beams over long distances without need for a confining magnetic field. Physical mechanisms of the beam formation, transport, intrinsic emittance with thermal effects, the...
We have successfully developed the vacuum-sealed carbon nano-tube (CNT) x-ray tube. The remarkable improvement of field emission properties, life time and stability, was obtained after high temperature brazing process in a vacuum circumstance.
Cadmium sulphide-polyaniline (CdS-PANI) nanotube composite was synthesized in two steps. Simple chemical oxidative polymerization has been used to synthesize PANI nanotubes in the first step, which are used further to form nanocomposite with CdS nanoparticles in the second step. The structural, optical and chemical properties of the CdS-PANI nanotube composite are revealed using XRD, UV-visible TEM,...
Zinc oxide was directly grown on the graphene layer by the hydrothermal synthesis method, and the field emission property of this hybrid structure was tested by a diode structure device. Compared with the Zinc oxide directly grown on the silicon substrates, the hybrid emitter shows better performance in the field emission properties, including low turn-on field, threshold field and high emission current...
We have developed highly adhesive carbon nanotube field emitters with a carbide filler. The adhesion was reinforced by a chemical reaction between the carbide filler and the substrate. We observed the field emission properties to be improved by the increment of the effective field emitters through repeated surface treatments.
In this work we present a carbon nanotubes electron source assembled with a low cost technique. We used a carbon nanotube cathode that reached the remarkable current density of 0,6 A/cm2. The cathode has been assembled with an external grid in a compact electron source that achieved a maximum output current density of 45 mA/cm2. This represents one the first examples of a CNTs electron source realized...
The diamond-like carbon films were prepared by filtered cathodic vacuum arc system. Surface morphology and microstructure of the films were investigated by atomic force microscope and Raman spectrum. The field emission properties of the film were tested under vacuum condition, and the turn-on field was found to be 1.3V/μm.
A macro-focus X-ray tube with CNT emitters was successfully developed. An anode current of 1.15mA was collected when the copper grid gate voltage was 2.7kV. A very small x-ray focal spot size with less than 39μm can be achieved, which could potentially produce very high special resolution X-ray image.
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