Nanoparticles of palladium and its oxides are synthesized on carbonic materials via the laser ablation and deposition of metals in electric fields. Studies of the materials show it is possible to control the crystallinity, size, and chemical state of nanoparticles without changing the laser beam parameters.

Palladium catalysts have been synthesized by electric field-assisted laser ablation at varying orifice voltage. The catalysts have been characterized by XPS and TEM and tested in the hydrogenation of isoprene and 2,5-dimethylhexadiene-2,4. High catalytic activity has been shown (TOFs = 397 and 158 s −1 for isoprene and 2,5-dimethylhexadiene-2.4, respectively).

Thin SnO 2 films grown by pulsed laser deposition have been characterized by X-ray diffraction, optical spectroscopy, and scanning electron microscopy. The carrier mobility and concentration in the films have been determined as functions of target composition (0–8 at % Sb) using Hall effect measurements, and the resistivity of the films has been measured by a four-probe technique. The lowest resistivity (ρ = 2 × 10 −3 Ω cm) and the highest transmission (≃ 85%) of the films in the spectral range 400-800 nm have been obtained at a target composition Sb/(Sn + Sb) = 2 at %. The observed variation in the resistivity of the films is determined by changes in carrier concentration to a greater extent than by changes in carrier mobility. X-ray photoelectron spectroscopy results demonstrate that the predominant charge state of the antimony in the films is Sb 5+ .

Pulsed laser ablation-deposition (PLA-PLD) in inhomogeneous electrical and electromagnetic fields was used to synthesise supported Pd catalysts. A modified PLA-PLD method opens up opportunities for obtaining Pd nanoparticles with the size from 2 to 5 nm by varying the deposition conditions. The catalysts were investigated by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS): The content of metal in catalysts was ultra-low (0.011-0.016 wt%). The catalysts demonstrated unexpectedly high activity for phenylacetylene semihydrogenation (TOFv 18-55 s(-1), TOFs 41-224s(-1)) at the Pd/substrate molar ratio less than 1/100000 and styrene selectivity up to 93%. (C) 2013 Elsevier B.V. All rights reserved.

Antimony-doped tin dioxide whiskers have been prepared by vapor growth in a tube furnace in a flowing mixture of argon and oxygen at a constant evaporation temperature. The antimony concentration was measured by laser mass spectrometry. Palladium was deposited by laser ablation. The palladium-modified whiskers exhibit a sensing response to CO at the level of its maximum allowable concentration in the workplace.

Методом роста из пара синтезированы нитевидные кристаллы диоксида олова, легированные сурьмой. Синтез проведен в трубчатой печи в потоке газовой смеси аргон + кислород при постоянной температуре испарения. Измерена концентрация введенной сурьмы методом лазерной масс-спектрометрии. Палладий наносили методом лазерного осаждения в вакууме. Показано, что нитевидные кристаллы, модифицированные палладием, обладают сенсорной чувствительностью по отношению к СО на уровне ПДКр.з.

Thin indium tin oxide (ITO) films have been grown on quartz glass substrates by pulsed laser deposition. The influence of ablation target composition and deposition conditions on the growth rate, optical transmission spectra, and carrier mobility and concentration of the films has been examined. The average surface roughness of the ITO films grown at substrate temperatures above 300°C is 2 nm. The films grown at an oxygen partial pressure of 5 mTorr using ablation targets with Sn/(In + Sn) = 5% possess high transmission (85-95%) in the visible range and low resistivity (1.8 × 10−4 Ω cm).

The effect of structure and charge composition of Pt laser plasma in the surface doping of SnO2 thin films on their resistive gas sensitivity towards hydrogen has been studied. The structure and charge composition of plasma varied depending on the value and polarity of the potential (U D ) of the inhomogeneous electrostatic field generated between a target and plates of a diaphragm located in a vacuum chamber outside the plasma dispersion zone under the action of Kr-F laser radiation on a platinum target. Doping at U D > 0 results in an increase in gas sensitivity of SnO2 films several times greater than doping by quasineutral plasma (U D = 0). The films doped at U D < 0 with surface concentrations of Pt optimum in terms of the maximum gas sensitivity appear to tolerant towards changes in the composition of the gas phase in a temperature range of 50–600°C.

The effect of the energy flux density of a pulsed Kr-F laser on the processes of generation of the laser plasma of tin, palladium and platinum and on the deposition rates of metal films on dielectric substrates in laser ablation have been studied. The use of the differential scheme of probing a laser plasma with Faraday cups and time-of-flight mass spectrometry has made it possible to distinguish, in plasma ion signals, the ranges of singly charged and multicharged ions, which differ in kinetic energy. The film deposition rate depends on both the laser energy flux density and the degree of ionization of the laser plasma.