Field emission properties of vertically aligned iron nanocluster wires grown on a glass substrate

Abstract

Vertically aligned nanocluster wires (NCWs) were synthesized on indium-tin-oxide-coated glass substrates via the thermal decomposition of Fe(CO)5 with a resistive heater under a magnetic field. The density of the aligned NCWs was controlled by varying the flow rate of the carrier gas. The low-density NCWs showed better field emission characteristics, with a low turn-on field of about 4V∕μm and a current density as high as 3mA∕cm2 at 7.6V∕μm. The field enhancement factor (γ) was determined to be ∼1200 for high-density NCWs and ∼1600 for low-density NCWs, which is comparable to those of carbon nanotubes.

Volatile Rhenium(I) Compounds with Re–N Bonds and Their Conversion into Oriented Rhenium Nitride Films by Magnetic Field-Assisted Vapor Phase Deposition

“…Due to the soft character of the Re­(I) central atom, the incorporation of harder donor atoms like oxygen and carbon is suppressed, and phase contamination is reduced. Beside these intrinsic (molecular) design, the effects of external parameters, such as electromagnetic fields are offering additional control on grain size and growth direction of as obtained films. − Furthermore, field-induced promotion of GaN nanowire growth rate was reported, while the application of external magnetic fields in hot filament CVD of Fe­(CO) 5 lead to the formation of anisotropic iron nanostructures, emphasizing the importance of external magnetic as additional growth parameter in MO–CVD. , To the best of our knowledge, this is the first report on the formation of rhenium nitride films via metal–organic CVD performed in an external magnetic field that remarkably influences the grain growth and orientation of crystallites when compared with CVD performed without an external field.…”

Anisotropy control in magnetic nanostructures through field-assisted chemical vapor deposition

“…Specifically, the microstructure evolution during the CVD process is challenging to manipulate by external stimuli and the experimental strategies are mostly limited to external orientation-aids, such as pre-structured surfaces, 6,7 templates 8 or external magnetic fields. 9 Kim and coworkers observed an anisotropic assembly of iron clusters during magnetic field-assisted hot filament CVD, 10,11 when iron nanoclusters formed in the gas phase were found to align on the substrate along the magnetic field lines. Luo et al applied magnetic fields during the growth of carbon nanotubes (CNTs) on nickel catalyst to demonstrate growth parallel to the field direction and elongation of catalyst particles that consequently favored the CNT growth in the direction of the applied field.…”

Magnetic Field-Assisted Chemical Vapor Deposition of Iron Oxide Thin Films: Influence of Field–Matter Interactions on Phase Composition and Morphology

“…An interesting field–matter interaction was described by Kang and co-workers during the hot filament CVD of Fe­(CO) 5 that produced anisotropic structures formed by field-induced assembly of iron nanoparticles that improved their field emission properties. However, to the best of our knowledge, there are no reports on the direct influence of external magnetic fields on the CVD of iron oxides, grown from molecular single-source precursors (such as [Fe(O t Bu) 3 ] 2 ), carrying the needed atomistic ratio for phase-pure iron oxide formation without the necessity of additional process gases or postannealing steps .…”