Radio Frequency Plasma Reactor Research Articles

Oxide coated nickel powder as support for platinum(0) nanoparticles: Magnetically separable catalysts for hydrogen generation from the hydrolysis of ammonia borane

We report the development of a novel method for the preparation of magnetically separable platinum nanoparticles. Magnetic nickel nanopowder is initially synthesized in a radiofrequency plasma reactor where in-line passivation was carried out with oxygen gas, resulting in the formation of nickel oxidecoated nickel particles. Following this, platinum nanoparticles are deposited onto the surface of the oxidecoated nickel nanopowder, forming Pt0/Ni@NiO nanocatalysts for the hydrolytic dehydrogenation of ammonia borane. The Pt0/Ni@NiO nanoparticles, containing 0.24 % wt. Pt, exhibit remarkable catalytic activity in the hydrolytic dehydrogenation of ammonia borane, with a turnover frequency of 468 (mol H2)×(mol Pt)−1×min−1 for releasing 3 equivalent H2 gas per mole of ammonia borane from its hydrolysis at 25 ºC. This heightened catalytic activity of Pt0/Ni@NiO nanoparticles is attributed to the favorable metal-support interaction between the platinum(0) nanoparticles and oxide surface, namely the bonding of platinum to the oxide surface, as elucidated by the XPS analysis. More importantly, Pt0/Ni@NiO nanoparticles can be separated from the reaction solution by using an external magnet.

Surface modification of recycled polymers in comparison to virgin polymers using Ar/O2 plasma etching

AbstractLow‐pressure plasma etching of a recycled polyethylene terephthalate (PET) film is studied in comparison to virgin PET and polypropylene (PP) using a capacitively coupled radio frequency (RF) plasma reactor. Recycled polymers are distinguished by increased impurity content and weakened mechanical properties, both affecting plasma etching and adhesion processes. Mild plasma conditions have been selected to maintain the material bulk properties of the polymers. The etch rates and the morphology of the polymer samples were thus determined at floating potential compared with etching at the RF electrode for varying argon/oxygen gas mixtures, etching duration, and sample size. Thermoanalytical and X‐ray techniques were used to characterize the polymer before and after the plasma etching treatment. Finally, adhesive‐tape peel tests proved that excellent adhesion of silver coatings can also be achieved on a plasma‐treated recycled PET film.

Eco-friendly approach to improve traits of winter wheat by combining cold plasma treatments and carbonization of subtropical biomass waste

This study aims to improve the quality and quantity of winter wheat by using the potential of combining the use of cold plasma and waste biorefinery products for improving wheat yield. Plasma was applied by a radio frequency (RF) plasma reactor operated with air for 180 s and 50 W. The waste biorefinery products, including pyroligneous acid, biochar, and azolla compost, were used as plant nutrition. The effects of cold plasma treatment and waste biorefinery products were determined by measuring plant photosynthesis, grain yield, and content of chlorophyll, carotenoids, anthocyanin, protein, and starch. The experiment was conducted during the cropping seasons 2016−18 in a randomized complete block design with four replications. The combination of cold plasma and pyroligneous acid increased the grain yield up to 40.0%. The photosynthesis rate was improved up to 39.3%, and total chlorophyll content up to 48.3% in both years. Seed plasma treatment combined with biochar application increased the starch content by 36.8%. Adding azolla compost increased the protein content by 35.4%. Using seed plasma treatment with biochar increased the microbial biomass carbon by 16.0%. The application of plasma and azolla compost increased the microbial biomass nitrogen by 29.0%.

A Compact, Fast, and Efficient Plasma Cleaner

We demonstrate the working of a compact, fast, and efficient plasma cleaner that utilizes the intense plasma generated in a radio frequency (RF) plasma reactor with metal electrodes. Our plasma cleaner’s effectiveness in cleaning substrates with different contaminants was studied and compared with a commercial plasma cleaner (HARRICK plasma PDC-32G-2) using optical imaging, water drop test and X-ray photoelectron spectroscopy (XPS). We used substrates contaminated with fingerprints, photoresist, and pump oil to study the cleaning performance of our plasma cleaner. Excellent substrate cleaning could be achieved in less than 2 min, which shows that the cleaning time is reduced by about 80% compared with the commercial plasma cleaner. The results also indicate that the cleaning performance is comparable or better than the commercial plasma cleaner, without even precleaning the substrates.

Continuum modelling of an asymmetric CCRF argon plasma reactor: Influence of higher excited states and sensitivity to model parameters

AbstractPrecise control of capacitively coupled radiofrequency (CCRF) plasma reactors is required to achieve desired outcomes in surface functionalisation and material synthesis processes. This necessitates detailed mapping of the large process parameter space and a thorough understanding of spatial and temporal variations of the plasma throughout the reactor. These goals can only feasibly be achieved with accurate numerical modelling. Previous numerical studies of CCRF discharges have implemented a range of simplifying assumptions to improve numerical tractability, such as small electrode spacing, radial uniformity, fewer active species and simplified boundary conditions, while neglecting self‐bias formation. Although this approach is useful in developing the methodology for continuum plasma modelling, it poses challenges for direct comparison with experimental data and for understanding the behaviour of plasma processes employed in the surface treatment of large, complex objects, or the synthesis of nanoparticles. Here we report the development of a two‐dimensional axisymmetric continuum model for a CCRF reactor with a pure argon 13.56‐MHz discharge using the finite element method. The large electrode spacing and reactor design result in two distinct discharge regions and the formation of a strong DC self‐bias on the powered electrode. The plasma discharge is studied as the pressure is varied from 0.1 to 0.3 Torr, over the radiofrequency input power range of 25–100 W, which leads to consistent enhancements of the electron density and self‐bias. The impact of the electron energy distribution function (EEDF) on the discharge is assessed, with the assumption of a Druyvesteyn EEDF resulting in a bulk electron density and temperature of 3.4 × 1015 m−3 and 3.3 eV, respectively, compared with 8.1 × 1015 m−3 and 1.9 eV in the Maxwellian case. The asymmetric power distribution throughout the reactor is quantified to build a reduced domain model with a lower computational cost. The effect of an electrically floating parallel plate electrode is assessed, resulting in a 42% higher bulk plasma potential as compared with the grounded case. The inclusion of resonant and 2p excited states of argon is shown to have a major impact on the discharge dynamics, leading to an order of magnitude reduction in bulk electron density. This study proposes a robust numerical model of a CCRF argon plasma discharge to facilitate future simulations of more complex discharges with important implications in plasma surface engineering and synthesis of materials.

Plasma Surface Polymerized and Biomarker Conjugated Boron Nitride Nanoparticles for Cancer-Specific Therapy: Experimental and Theoretical Study.

A new low-pressure plasma-based approach to activate the surface of BN nanoparticles (BNNPs) in order to facilitate the attachment of folate acid (FA) molecules for cancer-specific therapy is described. Plasma treatment of BNNPs (BNNPsPT) was performed in a radiofrequency plasma reactor using ethylene and carbon dioxide monomers. The carboxyl groups deposited on the surface of BNNPsPT were activated by N,N’-dicyclohexylcarbodiimide (DCC) and participated in the condensation reaction with ethylene diamine (EDA) to form a thin amino-containing layer (EDA-BNNPPT). Then, the DCC-activated FA was covalently bonded with BNNPsPT by a chemical reaction between amino groups of EDA-BNNPsPT and carboxyl groups of FA. Density functional theory calculations showed that the pre-activation of FA by DCC is required for grafting of the FA to the EDA-BNNPsPT. It was also demonstrated that after FA immobilization, the electronic characteristics of the pteridine ring remain unchanged, indicating that the targeting properties of the FA/EDA-BNNPsPT nanohybrids are preserved.

Investigation of surface boundary conditions for continuum modeling of RF plasmas

This work was motivated by a lacking general consensus in the exact form of the boundary conditions (BCs) required on the solid surfaces for the continuum modeling of Radiofrequency (RF) plasmas. Various kinds of number and energy density BCs on solid surfaces were surveyed, and how they interacted with the electric potential BC to affect the plasma was examined in two fundamental RF plasma reactor configurations. A second-order local mean energy approximation with equations governing the electron and ion number densities and the electron energy density was used to model the plasmas. Zero densities and various combinations of drift, diffusion, and thermal fluxes were considered to set up BCs. It was shown that the choice of BC can have a significant impact on the sheath and bulk plasma. The thermal and diffusion fluxes to the surface were found to be important. A pure drift BC for dielectric walls failed to produce a sheath.

Kinetic contribution of CO 2 /O 2 additive in methane conversion activated by non-equilibrium plasmas

Abstract A temperature-controlled and pressure-controlled coaxial dielectric barrier discharge (DBD) reactor was developed to decouple the thermal and kinetic effects of radio frequency (RF) discharge on methane conversion, and further to compare the kinetic behaviors of the mechanistically similar reactions of methane conversion with O2 and CO2 additives. A kinetic mechanism for RF plasma assisted methane conversion was assembled. The formation of products in the RF plasma reactor was measured with Gas Chromatography (GC–TCD) and the data were used to validate the kinetic model. The experimental and computational results showed the different kinetic roles of carbon dioxide and oxygen additives in methane conversion, due to the different dissociation and ionization energy of the two additive gases, as well as the thus produced electron energy distribution function (EEDF). Fuel oxidation by plasma generated O, O(1D), O2(a1 ∆g), O2(b1Σg+) and O+ in partial oxidation of methane was observed essential for methane consumption, which resulted in an increase in methane conversion rate, compared to pure methane pyrolysis and dry reforming of methane with CO2 additive. It was also found that dry reforming of methane with CO2 was by far the easier to produce the syngas as well as C2 hydrocarbon species, due to the weak oxidation ability of CO2 and also the significant deposition of the electron energy on CH4 dissociation in a dry reforming discharge mixture. This kinetic study produced comparative data to demonstrate the contribution of CO2/O2 additive in non-equilibrium plasma assisted methane conversion.

Functionalization of Ti-40Nb implant material with strontium by reactive sputtering

BackgroundSurface functionalization of orthopedic implants with pharmaceutically active agents is a modern approach to enhance osseointegration in systemically altered bone. A local release of strontium, a verified bone building therapeutic agent, at the fracture site would diminish side effects, which could occur otherwise by oral administration. Strontium surface functionalization of specially designed titanium-niobium (Ti-40Nb) implant alloy would provide an advanced implant system that is mechanically adapted to altered bone with the ability to stimulate bone formation.MethodsStrontium-containing coatings were prepared by reactive sputtering of strontium chloride (SrCl2) in a self-constructed capacitively coupled radio frequency (RF) plasma reactor. Film morphology, structure and composition were investigated by scanning electron microscopy (SEM), time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HR-TEM) was used for the investigation of thickness and growth direction of the product layer. TEM lamellae were prepared using the focused ion beam (FIB) technique. Bioactivity of the surface coatings was tested by cultivation of primary human osteoblasts and subsequent analysis of cell morphology, viability, proliferation and differentiation. The results are correlated with the amount of strontium that is released from the coating in biomedical buffer solution, quantified by inductively coupled plasma mass spectrometry (ICP-MS).ResultsDense coatings, consisting of SrOxCly, of more than 100 nm thickness and columnar structure, were prepared. TEM images of cross sections clearly show an incoherent but well-structured interface between coating and substrate without any cracks. Sr2+ is released from the SrOxCly coating into physiological solution as proven by ICP-MS analysis. Cell culture studies showed excellent biocompatibility of the functionalized alloy.ConclusionsTi-40Nb alloy, a potential orthopedic implant material for osteoporosis patients, could be successfully plasma coated with a dense SrOxCly film. The material performed well in in vitro tests. Nevertheless, the Sr2+ release must be optimized in future work to meet the requirements of an effective drug delivery system.

Numerical study of Si nanoparticle formation by SiCl4 hydrogenation in RF plasma

Nanocrystalline silicon (nc-Si) is a promising material for many applications related to electronics and optoelectronics. This work performs numerical simulations in order to understand a new process with high deposition rate production of nc-Si in a radio-frequency plasma reactor. Inductive plasma formation, reaction kinetics and nanoparticle formation have been considered in a sophisticated model. Results show that the plasma parameters could be adjusted in order to improve selectivity between nanoparticle and molecule formation and, thus, the deposition rate. Also, a parametric study helps to optimize the system with appropriate operating conditions.

VUV spectroscopy of carbon dust analogs: contribution to interstellar extinction

A full spectral characterization of carbonaceous dust analogs is necessary to understand their potential as carriers of observed astronomical spectral signatures such as the ubiquitous UV bump at 217.5 nm and the far-ultraviolet (FUV) rise common to interstellar extinction curves. Our goal is to study the spectral properties of carbonaceous dust analogs from the FUV to the mid-infrared (MIR) domain. We seek in particular to understand the spectra of these materials in the FUV range, for which laboratory studies are scarce. We produced analogs to carbonaceous interstellar dust encountered in various phases of the interstellar medium: amorphous hydrogenated carbons (a-C:H), for carbonaceous dust observed in the diffuse interstellar medium, and soot particles, for the polyaromatic component. Analogs to a-C:H dust were produced using a radio-frequency plasma reactor at low pressures, and soot nanoparticles films were produced in an ethylene (C$_2$H$_4$) flame. We measured transmission spectra of these thin films (thickness < 100 nm) in the far-ultraviolet (190 - 250 nm) and in the vacuum-ultraviolet (VUV; 50 - 190 nm) regions using the APEX chamber at the DISCO beam line of the SOLEIL synchrotron radiation facility. These were also characterized through infrared microscopy at the SMIS beam line. We successfully measured the transmission spectra of these analogs from {\lambda} = 1 {\mu}m to 50 nm. From these, we extracted the laboratory optical constants via Kramers-Kronig inversion. We used these constants for comparison to existing interstellar extinction curves. We extend the spectral measurements of these types of carbonaceous analogs into the VUV and link the spectral features in this range to the 3.4 {\mu}m band. We suggest that these two materials might contribute to different classes of interstellar extinction curves.

Acrylic acid plasma polymerized poly(3-hydroxybutyrate) membranes for methanol/MTBE separation by pervaporation

Plasma polymerized acrylic acid (AA) thin films on poly(3-hydroxybutyrate) (PHB) membranes were evaluated as composite membranes for methanol/methyl tert-butyl ether (MTBE) separation by pervaporation (PV). Composite membranes were prepared in an inductively coupled radiofrequency plasma reactor. Experiments were performed at different powers (7.2 to 29.2W) and pressures, using pure AA monomer, as well as AA/air and AA/argon mixtures. Depositions chemical characteristics were determined through FTIR spectroscopy, hydrophilic character through contact angle measurements, and SEM images were also taken to analyze surface morphology. In PV measurements, membranes were methanol selective; the separation factor exceeded that of pure PHB membranes in all cases. Fluxes were lower than the original membrane but the performance separation index (PSI) was always higher. Results presented in terms of permeability were between 660 and 4045barrer for methanol, while for MTBE they were markedly lower, between 10.5 and 57.7barrer. These large differences in permeabilities caused high selectivities which ranged from 24 to 79.

Production of plasma polymer films with controlled composition and surface charge for selective cell adhesion

Event Abstract Back to Event Production of plasma polymer films with controlled composition and surface charge for selective cell adhesion Sara Babaei1 and Pierre-Luc Girard-Lauriault1 1 McGill University, Chemical Engineering Department, Canada Introduction: Under physiological condition, the adhesion of cells to a biomaterial is mediated mainly by presence of a protein layer. The adhesion of proteins to a biomaterial mainly depends on the surface physico-chemical properties; such as functional groups, surface energy, roughness and surface charge[1]. Among others, primary amines and carboxylic acid groups participate in rendering surfaces bioactive through the immobilization of biomolecules; therefore, nitrogen and oxygen based functional groups have been shown to be of high importance for biomedical applications. For instance, it has been previously reported that specific cell lines adhere to the amine rich coatings only if they contained a minimum amount of primary amine content. In this regard, it is possible to obtain adhesion-deterrent to adhesion-promoting surfaces for a specific cell type[2]. In this study, organic films with tunable oxygen/nitrogen functional group content and surface charge were produced by low-pressure plasma co-polymerization of binary gas mixtures of a hydrocarbon (ethylene/butadiene) and a hetroatom containing gas (carbon dioxide/ammonia) for the purpose of selective cell adhesion. Plasma polymerization parameters give direct control over the chemistry of the prepared surface, thus its surface charge can be easily adjusted. This study emphasizes on studying the chemical composition and surface charge of plasma polymers by using a combination of characterization techniques followed by investigation of surface parameters which affect protein adhesion (fibrinogen, fibronectin) with the objective of gaining an understanding of the links between surface characteristics of N and O rich plasma polymer films and cell adhesion. Materials and Methods: Plasma depositions were performed in a capacitive-coupled radio frequency plasma reactor. In order to produce plasma polymers with different surface characteristics, the gas flow ratio of the heteroatom gas source/hydrocarbon source gas, R, and has been changed between experiments. The coatings were analyzed to determine the chemical composition, evaluated by X-ray photoelectron spectroscopy (XPS), chemical derivatization and infrared reflection-absorption spectroscopy (IRRAS). The surface charge of plasma polymers films deposited in various conditions was evaluated by measuring their zeta-potential using an electro-kinetic analyzer (EKA). The protein adhesion to different plasma polymer coatings was evaluated by surface plasmon resonance (SPR). Results and Discussion: The results show that the [N] and [-NH2] of nitrogen rich coatings rise nearly linearly with increasing R. The [O] and [-COOH] concentration of oxygen rich coatings at different R values also show an almost linear increasing trend. The nitrogen rich films acquire positive surface charge due to existence of amine groups and in the same fashion, carboxyl groups in oxygen-rich coatings result in negative surface charges at physiological pH. In agreement with XPS results the absolute value of zeta potential increases by increasing the flow ratio in both nitrogen and oxygen rich coatings, due to more abundant amine and carboxylic groups, respectively (Fig 1). The SPR results showed a surface composition dependent protein adhesion to both nitrogen rich and oxygen rich plasma polymers, Fig 2. Conclusion: It has been shown that the surface composition of O- and N- rich plasma polymers provide control over the surface charge when immersed in aqueous solutions at physiological pH and promote fibrinogen adhesion. McGill Engineering Doctoral Award (MEDA); Natural Sciences and Engineering Research Council of Canada (NSERC); Fonds de Recherche du Québec - Nature et Technologies (FRQNT)

Thermochemical Assessment of Gasification Process Efficiency of Biofuels Industry Waste With Different Plasma Oxidants

Thermochemical assessment of the gasification of the biomass waste composed of sugarcane bagasse aiming for practical applications of an electric arc or radio frequency plasma reactors for the syngas production was carried out, considering different gasifying agents and their mixture (steam + air). The analysis of the calculations in the thermodynamic equilibrium shows that steam is the most efficient oxidant. In this case, the predicted optimum regime corresponds to the value of steam–biomass ratio of 0.4 at the temperature 1000 K (at ambient pressure), and for these conditions the maximum value of the energy efficiency is 0.91 and the value of the exergy efficiency is 0.84.

A linear radio frequency plasma reactor for potential and current mapping in a magnetized plasma.

Langmuir probe measurements in front of high power ion cyclotron resonant frequency antennas are not possible or simply too noisy to be analyzed properly. A linear experiment is a radio frequency (RF) magnetized plasma discharge reactor designed to probe the rectified potential in front of such antennas but at low power level (1 kW) to next improve antenna design and mitigate sheath effects. The maximum magnetic field is 0.1 T, and the RF amplifier can work between 10 kHz and 250 MHz allowing ion cyclotron resonances for argon or helium. The first measurements with no magnetic field are presented here, especially 2D potential maps extracted from the RF compensated probe measurements yield ni ≈ 10(15) m(-3) and Te ≈ 2 eV for RF power lower than 100 W. Series resonances in the chamber are highlighted and allow to deduce the plasma parameters from a simple equivalent impedance model of the plasma in helium gas. Next studies will be focused on magnetized plasmas and especially magnetized RF sheaths.

Solid State Electrochromic Devices of Plasma Modified WO3Hybrids

Electrochromic (EC) properties of tungsten trioxide (WO3) was improved with preparing hybrids of tungsten trioxide–titanium dioxide (WO3–TiO2) and tungsten trioxide–poly(3,4-ethylenedioxythiophene) (WO3–PEDOT) by a rotating capacitively coupled radio frequency (rf 13.56 MHz) plasma reactor. Energy-dispersive X-ray spectroscopy mapping results indicated that TiO2 and PEDOT were coated homogeneously onto the surface of the WO3 powders. Thin films of hybrid powders have been prepared by the physical vapor deposition method of the electron beam evaporation technique. Redox potentials, optical contrast at 700 nm, and durability during 2000 cycles of EC devices were investigated, comparatively. Hybrids of WO3 indicated excellent coloration efficiency (cm2 C–1) and switching speed values compared with untreated WO3. The coloration efficiency values were found to be 85.88 and 41.61 cm2 C–1 of WO3–TiO2 and WO3–PEDOT, respectively. The switching speed of WO3 (13.3 s, from bleached state to colored state) increased ...

Effect of cold oxygen plasma treatment on mechanical properties of phenylenebenzobisoxazole fiber-filled cross-linked polyethylene composites

Mechanical strength of phenylenebenzobisoxazole (PBO) fibers and cross-linked polyethylene (XLPE) matrix composites were studied with particular interest on the effects of oxygen cold plasma-treated fibers. PBO fibers were treated in a radio frequency plasma reactor using oxygen for different treatment times to increase the interface adhesion. Tensile tests on PBO fibers showed that plasma treatment caused an increase in average tensile strength compared with untreated fibers. Fracture analysis confirmed the increase in interfacial adhesion due to oxygen plasma treatment.

Effect of Plasma Modification of Copper Nanoparticles on their Antibacterial Properties

Surface modification of copper nanoparticles (CuNPs) was performed in a radiofrequency plasma reactor using acrylic acid, acrylonitrile, and methyl methacrylate monomers. Treated and untreated CuNPs were analyzed by thermogravimetrical analysis, X-ray diffraction (XRD), transmission electronic microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The oxidation of CuNPs was assessed by XRD as a function of the plasma treatment. The antibacterial properties of plasma treated CuNPs were evaluated using Pseudomonas aeruginosa and Staphylococcus aureus. It was found that the plasma modification did not affect significantly the antibacterial properties of CuNPs, since the plasma films deposited on their surfaces were in the order of few nanometers and copper ions traveled easily through the plasma polymer to interact with the bacteria. Further, the nanocoating deposited by plasma on the CuNPs protects them against the oxidation even in solution dispersions. CuNPs coated with acrylonitrile presented a slightly lower antibacterial activity than pristine CuNPs.

Improving stability of TiO2 particles in water by RF-plasma polymerization of poly(acrylic acid) on the particle surface

The stability of TiO2 particles in water was increased through plasma polymerization of acrylic acid (AA) onto the particles surface. The polymerization was carried out directly upon TiO2 powder by using two radiofrequency (RF) plasma reactors: one inductively coupled and another capacitively coupled. In both cases, a cross-linked polyacrylic acid (PAA) film was formed on TiO2 particles surface, which was characterized by Energy Dispersive Spectroscopy (EDS), Fourier-transformed infrared spectroscopy, (FTIR), Raman Spectroscopy, and X-ray photoelectron spectroscopy (XPS). The stability of the PAA-coated TiO2 particles was determined by their precipitation in water. It was found that a moderate plasma treatment effectively improved the stability of PAA-coated TiO2 particles. At low levels of AA polymerization, the TiO2 particles surface was not modified enough to improve their stability in water; on the other hand, a high degree of AA polymerization led to the formation of large agglomerates, induced by the PAA film, and these particles were not stable. As expected, the particle size and the Z-potential of the PAA-coated particles determined their stability in water. Under the optimum operating conditions of this study, the treated TiO2 particles showed stability as good as that of TiO2 particles modified with a dispersant.

Characteristics of Synthesized Alumina Nanoparticles in a High-Pressure Radio Frequency Thermal Plasma Reactor

Nanophase alumina is synthesized in an atmospheric pressure radio frequency (RF) plasma reactor through melting, evaporation, and vapor phase nucleation technique. A specially designed high-pressure RF plasma reactor fitted with an indigenously built RF plasma torch converts commercially available micrometer size alumina chunks into spherical nanophase alumina in a single step under ambient quenching conditions without use of any additional quenching gas. Obtained powder contains mixed phases of α and δ -alumina as revealed by X-ray diffraction studies. Transmission Electron Microscopy analyses exhibit very small particle size (peak at 15 nm), narrow size distribution (half width ~ 24 nm), zero agglomeration, and good crystallinity. Obtained particle characteristics together with the high purity owing to inherent electrode-less feature of the RF discharge are suitable for important technological applications including fabrication of high-power ceramic laser gain media like Y3Al5O12 (YAG) from composites of Al2O3 and Y2O3. Characteristics of the synthesized alumina are compared with that of nanoalumina synthesized in atmospheric arcs.