Abstract: A method for the production of elemental carbon fibers and carbon particles uses highly uniform catalyst particles, preferably made by laser pyrolysis. Preferred catalyst particles include elemental iron, iron carbides or iron sulfides, generally with an average particle diameter from about 1000 nm to about 5 nm. Also, preferred catalyst particles have a narrow distribution in particle diameters as well as a cut off in particle size that the diameter distribution does not have a tail toward large diameters.

Abstract: The stoichiometry and/or crystal structure of vanadium oxide particles are altered by heating initial particles of vanadium oxide under mild conditions. The temperature is generally at least about 300.degree. C. less than the melting point of both the initial vanadium oxide particle and the product vanadium oxide particles. Preferred initial particles are vanadium oxide nanoparticles. The heating can be performed under an oxidizing atmosphere or an inert atmosphere, depending on the particular initial particles and the desired product particles.

Abstract: Polymer based solar cells incorporate nanoscale carbon particles as electron acceptors. The nanoscale carbon particles can be appropriate carbon blacks, especially modified laser black. Conducting polymers are used in the solar cells as electron donors upon absorption of light. Preferred solar cell structures involve corrugation of the donor/acceptor composite material such that increased amounts of electricity can be produced for a given overall area of the solar cell.

Abstract: An apparatus efficiently produces of particles from gas phase chemical reactions induced by a radiation beam. The apparatus includes a reaction chamber and an elongated reactant inlet, where the reaction chamber is configured to conform generally to the elongated shape of the reactant inlet. Shielding gas may be introduced to form a blanket of inert gas on both sides of the reactant stream. A feed back loop may be used to maintain the desired pressure within the reaction chamber.

Abstract: Batteries based on nanoparticles are demonstrated that achieve high energy densities. Vanadium oxide nanoparticles can have several different stoichiometries and corresponding crystal lattices. The nanoparticles preferably have average diameters less than about 500 nm and more preferably less than about 150 nm. Cathodes produced using the vanadium oxide nanoparticles and a binder can be used to construct lithium batteries or lithium ion batteries. The nanoparticles may have energy densities greater than about 900 Wh/kg.

Abstract: Electromagnetic shielding material is formed from a shielding composition made with magnetic particles and a binder, where the magnetic particles have an average diameter less than about 1000 nm and are substantially crystalline. The magnetic particles can be formed from Fe.sub.2 O.sub.3, Fe.sub.3 O.sub.4, Fe.sub.3 C, or Fe.sub.7 C.sub.3. The shielding composition can be formed into a layer or into composite particles. The binder can be a metal or an electrically conducting polymer. A conducting layer can be placed adjacent to the shielding composition. The shielding material can be used to protect sensitive electronic devices. Methods are described for forming iron oxide particles by laser pyrolysis.