Laser-ablated metal vapor

Alternative Thin-Film Fabrication Approaches. Thin films of electronic ceramic materials have also been prepared by sputtering, electron beam evaporation, laser ablation, chemical beam deposition, and chemical vapor deposition (CVD). In the sputtering process, targets may be metal... 

Despite the frequent use of arc-discharge and laser ablation techniques, both of these two methods suffer from some drawbacks. The first is that both methods involve evaporating the carbon source, which makes it difficult to scale up production to the industrial level using these approaches. Second, vaporization methods grow CNTs in highly tangled forms, mixed with unwanted forms of carbon and/or metal species. The CNTs thus produced are difficult to purify, manipulate, and assemble for building nanotube-device architectures in practical applications. 

There are some variants that have emerged in the wake of DESI. By replacing the electrospray emitter by a metal needle and allowing solvent vapor into the coaxial gas flow desorption APCI (DAPCI) can be performed [106], Other versions are atmospheric-pressure solids analysis probe (ASAP) where a heated gas jet desorbs the analyte, which is subsequently ionized by a corona discharge [107], and electrospray-assisted laser desorption/ionization (ELDI) where a laser ablates the analyte and charged droplets from an electrospray postionizes the desorbed neutrals [108],... 

Huang and Freiser (132, 133) were able to prepare exohedral metal C60 ions [MC60]+ by direct reaction of the bare metal ions Fe+, Ni+, Co+, Cu+, Rh+, and La+ with Cgo vapor produced from a heated probe. The [MC60]+ ions when subjected to low-energy collision-induced dissociation with argon all produced the Cg0 ion. These results show that the metal ions attach to the outer surface of C60. The exohedral metallofullerene ions differ from the endohedral metallofullerenes produced by laser ablation of metal oxide-graphite mixtures and support the observations of Smalley and co-workers (148) who found that endohedral metallofullerene ions dissociate by loss of C2 units. 

Rapid solidification and devitrification of amorphous metals and metallic glasses Combustion-flame chemical vapor condensation processes (Kear) Induction-heating chemical vapor condensation processes DC and RF magnetron sputtering, inclusive of the method of thermalization Laser ablation methods Supercritical fluid processing... 

A Co/Ni alloy is the next active catalyst among the binary combinations within the iron-group metals in the arc discharge method (51). Laser vaporization of metal/ carbon composite in argon atmosphere at high temperature (1200°C) can also produce SWNTs (41). Guo et al. (41) reported that the Co/Ni alloy was the most effectual, with a yield of 50-90% in the laser ablation method. 

The top-down approach starts with a bulk material and attempts to break it down into nanoscaled materials through physical methods. Hence, most of these techniques are really forms of fabrication rather than synthesis. For nanostructured bulk phases, including powders, the common methods are milling, devitrification of metallic glass, and severe plastic deformation. For nanocrystalline thin films (films with nanosized crystallites), methods include thermal vaporization (under high vacuum), laser ablation, and sputtering (thermal plasma), all of which were... 

Another key factor in the popularity of the technique is its increasingly widespread use in speciation chemistry. The current awareness of the importance of the chemical form in which an element is present in food (e.g., the oxidation state, the nature of the ligands, and the molecular structure), on its possible absorption and fate inside the body, has made elemental speciation a prominent topic of present research in the food science. If speciation critically influences the bioavailability, essentiality, or toxicity of an element, the analytical techniques that enable species discrimination and quantification gather prominence. ICP-MS has the capability for quantifying metal (metalloid)-containing species in a chromatographic or capillary electrophoresis effluent or, as recently demonstrated, in a gel spot after SDS-PAGE via electrothermal vaporization (ETV) or laser ablation (LA) [4, 5]. Hence, it has firmly established as a sensitive,... 

SWCNTs exhibit unique physical and chemical properties that make them very attractive candidates for the production of new materials. Carbon nanotubes are made by wrapping up single sheets of graphite, known as graphene, upon themselves to form hollow, straw-like structures. Traditionally, SWCNTs have been prepared by electric arc-discharge, laser ablation and chemical vapor deposition (CVD) methods these techniques produce significant quantities of impurities, such as amorphous and graphitic forms of carbon and encapsulated catalytic metal nanoparticles. 

Several factors affect the growth of SWNTs in the laser-ablation technique. Extensive studies on the development of the laser-vaporization technique have optimized the process conditions such as laser parameters, composition of graphite and metal, carrier gas, pressure, and temperature. Through these studies, a sigiuficant understanding of the SWNT s growth and propagation under laser-vaporization condition is achieved. ... 

Mixed metal oxides can be addressed as belonging to three main fields, namely superconducting metal oxides (SMOs) (Section V.D.l), transparent conductive oxides (TCOs) (Section V.D.2) and ferroelectric oxides (Section V.D.3). The synthesis procedures for mixed metal oxides include sintering, sol-gel, PLD or laser ablation, sputtering evaporation, MBE, MOVPE (metal-organic vapor-phase epitaxy), OMVPE (organometallic vapor-phase epitaxy) and CVD in particular. 

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