Effect Of Ion Beam Treatment Research Articles

Effects of Ion Beam Treatment on DC Flashover Characteristics of Epoxy

The effect of ion beam treatment on surface flashover characteristics of epoxy is evaluated and explored. Epoxy samples are prepared and ion beam treatment is carried out for 10-, 15-, 20-, 25-, and 30-min durations using an end-Hall ion source. Flashover test of both pristine and treated samples is conducted at negative dc voltage in air. The results indicate the effectiveness of ion beam treatment to enhance the flashover properties of epoxy. The flashover voltage of the epoxy resin increased to 21.35% after ion beam treatment for a duration of 20 min. Optical microscopic images, scanning electron microscopy (SEM) images, and results from Fourier transform infrared spectroscopy reveal the change in physicochemical characteristics of epoxy resin after treatment. The obtained surface potential from the surface potential decay (SPD) test shows a faster decay rate of surface charges for treated samples than the pristine epoxy. Moreover, from the trap distribution characteristics, it is found that ion beam treatment reduces the surface trap depth, which increases the surface conductivity of the epoxy insulator and helps to promote the charge migration and transport along the insulator surface.

Effect of Ion-Beam Treatment on the Structure and Properties of Titanium-Oxide Films

Effect of Ion-Beam Treatment on the Structure and Properties of Titanium-Oxide Films

Влияние ионно-лучевой обработки в процессе ВЧ магнетронного распыления на свойства плeнок ZnO

The effect of ion-beam treatment, alternating with the magnetron sputtering process, on the properties zinc oxide of thin films is considered. Ion-beam treatment causes a decrease in the growth rate, the size of the coherent scattering regions and resistivity. The stoichiometric index, the band gap and the refractive index increase. The transparency of the films in the area of weak absorption does not change.

IP-Dip photoresist surfaces for photonic applications prepared by laser lithography and studied by AFM

To summarize, this paper explores new application of laser lithography based on direct laser writing and focused ion beam technique, to pattern optically smooth surface of IP-Dip polymer for photonic devices and on-chip photonic applications. The surface image in nanometer scale was obtained by atomic force microscope. The surface analysis was made in XEI commercial software by use of areal roughness parameter Sq. We have found that with this technique we can obtain much better results than the Raileigh criterion for smoothness. Finally, we found optimal process parameters of laser lithography for optically smooth surfaces and demonstrated the effect of ion beam treatment on surface quality.

The Effect of Ion-Beam Treatment on the Mechanical, Morphological, and Biocompatible Properties of Titanium Medical Products

A technique for the formation of the quasi-porous structure of a Ti surface with craters that are formed by helium blistering was developed. It was found that the quasi-pores with a size of 10–50 μm were formed on the Ti surface because of flaking and exfoliation of blister domes under the implantation of He+ ions with an accelerating voltage of 100–200 kV and implantation fluence of 6 × 1017–6 × 108 cm–2. A subsequent irradiation with Ar+ ions in a carbon dioxide medium led to an increase in the microhardness of the quasi-porous Ti by 20–30%. The maximum increase in the microhardness was observed for the Ar+ ion fluence of 2 × 1016 cm–2. It was shown that the fatigue strength of the Ti with the quasi-porous surface that was formed by the He+ implantation depended on the fluence of Ar+ ions and also had the maximum value at the fluence of 2 × 1016 cm–2. The results obtained are explained by ion-induced modification of the structure and composition of the surface layers. In vivo experiments showed that the Ti implants with double implantation of He+ and Ar+ ions had enhanced biocompatibility and high osseointegration capacity of the surface.

Effect of ion beam treatment (Ar+, E = 30 keV) on the microstructure of titanium alloys

The effect of continuous Ar+ ion beams (E = 30 keV, j = 400 μA/cm2; F = 5·1016 cm-2) on the hardness and microstructure of the Gr2-titanium-based and Ti-6Al-4V alloys after cold working and subsequent recrystallization annealing is studied. It has been found that the initial microstructure of the annealed alloys in the equilibrium state, which consisted of recrystallized equiaxed grains, does not change after irradiation; thus the hardness of the irradiated samples is comparable with that of the initial samples. The initial fine fiber structure of the deformed Ti-6Al-4V alloy changes insignificantly after both annealing (T = 790°C, 30 min) and ion irradiation under used conditions. In contrast to that, the effect of rapid radiation annealing of the cold-worked titanium Gr2 alloy with beams of accelerated ions of inert gas at low temperatures (lower by 130°C than the conventional annealing temperature of these alloys at 680°C) and for a shorter time (9 min instead of 35 min, τirr ∼ 20 s) has been revealed. The result is the formation of a uniform recrystallized structure with equiaxed fine grains 5-10 μm in size in the entire volume of the 3-mm-thick samples, despite the fact that the average projected range of 30-keV Ar+ ions in titanium is only 20 nm.

Effect of ion-beam treatment during reactive radio-frequency magnetron sputtering on the concentration and mobility of charge carriers in ITO films

It is shown that ion-beam treatment during the deposition of ITO films by reactive radio-frequency magnetron sputtering induces a decrease in the resistivity of the films even at room temperature. Variations in the Hall mobility and concentration of charge carriers are studied in relation to the condensation temperature and ion-beam treatment current. The resistivity decreases mainly because of an increase in the concentration of majority charge carriers. It is inferred that the change in the concentration of charge carriers is associated with {ie1237-1} defects.

Effect of ion-beam treatment during reactive high-frequency magnetron sputtering on macrostresses in ITO films

Transparent conductive tin-doped indium-oxide films are produced by alternate processes of reactive high-frequency magnetron sputtering and ion treatment. The stressed states of the indium-tinoxide (ITO) films are studied by X-ray diffraction analysis. The effect of the technological conditions on changes in mactostresses in the ITO films is shown.

Electrical properties of indium-tin-oxide films treated with an intense ion beam current

The authors investigated the electrical properties of low-temperature-deposited indium-tin-oxide (ITO) films treated with an argon-ion beam (AIB) at high current density and low energy. Experimental data showed that ITO films on PET substrates treated in this manner had higher conductivity than the PET films treated thermally. X-ray diffraction indicated that the AIB ITO films had a poly-crystalline-like structure and that amorphous regions were present in PET substrates. Scanning electron microscopy (SEM) showed that the AIB ITO film surfaces had smaller cracks and exhibited dense bonding, presumably caused by instantaneous melting of ITO films by the high-current AIB beam. Consequently, the authors speculate that the effects of ion-beam treatment are driven by surface heating due to atomic collisions.

The Effect of Ion-Beam Treatment on TiO2Coatings Deposited on Polycarbonate Substrates

The effect of an Ar plasma treatment on polycarbonate substrates was investigated using <TEX>$TiO_2$</TEX> coatings produced by reactive ion-beam assisted sputtering. The typical pressure used during sputtering was about <TEX>$10^{-4}$</TEX> Torr. After the Ar plasma treatment, the contact angle of a water droplet was reduced from <TEX>$88^{\circ}$</TEX> to <TEX>$52^{\circ}$</TEX> and then further decreased to <TEX>$12^{\circ}$</TEX> with the addition of oxygen into the chamber. The surface of the polycarbonate substrate hanged from hydrophobic to hydrophilic with these treatments and revealed its changing nano-scale roughness. The <TEX>$TiO_2$</TEX> films on the treated surface showed various colors and periodic ordering dependant on the film thickness due to optical interference.

Effects of ion beam treatment on atomic and macroscopic adhesion of copper to different polymer materials

Low-energy ion irradiation of polymer induces different phenomena in the near surface layer, which effect strongly the metal–polymer interface formation and promotes adhesion of polymers to metals. Low-energy argon and oxygen ion beams were used to alter the chemical and physical properties of different polymers (PS (polystyrene), PαMS (poly(α-methylstyrene), BPA-PC (bisphenol-A-polycarbonate) and PMMA (poly(methyl methacrylate)), in order to understand the adhesion phenomena between a deposited Cu layer and the polymers. The resulting changes were investigated by various techniques including X-ray photoelectron spectroscopy, measurements of the metal condensation coefficient and a new technique to measure cross-linking at the polymer surface. Two types of practical adhesion strengths of Cu–polymer systems, measured using 90° peel tests, were observed: (i) peel strength increased at low ion fluences, reached a maximum and then decreased after prolonged treatment and (ii) no improvement in the peel strength on treated polymer surfaces was recorded. The improvement in the metal–polymer adhesion in the ion fluence range of 10 13–10 15 cm −2 is attributed to the creation of a large density of new adsorption sites resulting in a larger contact area and incorporation of chemically active groups that lead to increased interaction between metal and polymer by metal–oxygen–polymer species formation. XPS analysis of peeled-off surfaces showed that in most cases the failure location changed from interfacial for untreated polymers to cohesive failure in the polymer for treated surfaces. These observations and measurements of the metal condensation coefficients suggest that bonding is improved at the metal–polymer interface for all metal–polymer systems. However, the decrease in the peel strength at high ion fluences is attributed to the formation of a weak boundary layer in polymers. The correlation between sputter rate of polymers and altering in the peel strength for moderate ion fluences was determined. It was observed that the metal–polymer adhesion could be improved for PS and BPA-PC, which have a low sputter rate and preferentially formed cross-links in the treated surface. For degrading polymers, like PαMS and PMMA, chain scission rather than cross-linking dominates, low molecular weight species are formed and no adhesion enhancement is observed.

The effects of ion beam treatment on the interfacial adhesion of Cu/polyimide system

In microelectronics packaging, the reliability of the metal/polymer interface is an important issue, as the adhesion strength between dissimilar materials is often inherently poor. The modification of polymer surfaces using Ar ion beam irradiation and RF plasma deposition has been commonly used to enhance the adhesion strength of the interface. In this study, the treatment of polyimide surfaces with Ar or O2 ion beam irradiation and the DC magnetron sputtering of Cu films were adopted to prepare the specimens of Cu/polyimide systems. The results indicate that the peel strength increases as the Ar or O2 ion beam irradiation energy increases at a fixed metal-layer thickness. Additionally, the treatment of polyimide surfaces using O2 ion beam irradiation showed a higher peel strength than if Ar ion beam irradiation was utilized. This increase in peel strength mainly results from an increase in the surface roughness as well as an increase in the functional group on the polyimide film, both caused by ion beam irradiation.

Surface modification of superalloys and heat resistant steels by irradiation of low and high energy ion beams

The effect of ion beam treatment (IBT) using low and high energy ion beams, on surface topography, chemical composition and structure of surface layer and service properties of nickel based superalloys, heat resistant steels and pure Ni was studied. It was shown that low energy high current IBT ( E ≈ 10 −1 to 10 ° keV, j ≈ 10 −1 to 10 mA cm −2) enabled: (1) to form a surface of irradiated samples with a roughness varying over a wide range; (2) to carry out radiation-enhanced relaxation of residual stress, formed during pretreatment; (3) to clean the surface layers of the sample from contamination by C, O and S; (4) to detect the cast superalloy macrostructure. The results of gas and metal ion implantation investigation indicate that at the traditional regimes of implantation ( E ≈ 10 keV, < j> ≈ 10 μA cm −2, D ≈ 10 17 ions cm −2), the depth of ion penetration is 10 −2 to 10 −1 μm and the thickness of the modified structure layer is h M ≈ 10 −1 μm. One can increase the h m considerably by high current ion implantation (j≥10 3 μA cm −2) and high power pulse IBT ( N p≥10 7 W cm −2, τ p ≈ 10 1 to 10 2 ns). The irradiation by high energy ion beams allows to change the service properties of the materials (wear resistance, oxidation resistance, fatigue strength) over a wide temperature range. Plausible reasons of these changes are discussed.

The influence of ion-induced surface modification on stress corrosion cracking of aluminium alloys

There have been very few studies on the effect of ion beam treatment on stress corrosion cracking. Therefore ion implantation of Mg, ion beam mixing of Zr thin films and ion-beam-assisted deposition of Si were used for modifying the surface of aluminium alloys and pure aluminium. Corrosion measurements under pitting conditions and stress corrosion conditions were performed. Auger electron spectroscopy depth profiling and electron diffraction were used to determine the composition and structure respectively of selected samples. The stress corrosion samples were made of Al alloy 7475 T651 according to DIN 50 125. For the pitting measurements polished pieces of an Al rod with a purity of 99.5% were used. The pitting measurements were performed in aerated aqueous solution of 2% NaCl at 25 °C. The resistance against stress corrosion cracking was measured using a method according to ASTM G44, i.e. alternating immersion in an aqueous solution containing 3.5% NaCl under a constant strain of 100 MPa. The results of the measurements showed that it is possible to inhibit the initiation of stress corrosion cracking of Al alloys for a prolonged period by application of several different ion-induced surface modifications. Under the given conditions it seems that pitting is not a prerequisite for stress corrosion cracking.

The effect of ion beam treatment and subsequent annealing on Au/GaAs contacts

The effect of Xe++ and Ar+ ion beam treatment and subsequent annealing on the Au (55 nm)/n-GaAs system was studied using cross-sectional transmission electron microscopy. The maximum depth of observed defects caused by Xe++ ions (700 keV, 1×1014 ions/cm2) was about 400 nm from the interface in excellent agreement with the results of capacitance-voltage measurements. The formation of about 50-nm-thick polycrystalline region of GaAs was observed. The ion beam treatment resulted in the formation of defects (stacking faults, twins) down to a depth of 200 nm measured from the interface. Between 200 and 400 nm depth dislocation loops were formed. Amorphization has not been observed. The sharp Au/GaAs interface has been only slightly destroyed in the as-implanted sample. In contrast to pits in unirradiated samples, large flat grains of Au(Ga) solid solution grown into the highly damaged region of GaAs were found in the samples annealed at 450 °C after the ion beam treatment. The formation of a regrown GaAs covering layer was observed on the top of the reacted metallization. High dose implantation of Xe++ ions resulted in the formation of an amorphous GaAs layer with a thickness of about 750 nm. A phase transition caused by the ion beam was observed in this sample. During annealing at 400 °C the whole amorphous GaAs region recrystallized to single-crystal GaAs. Ion beam treatment with Ar+ ions (400 keV, 2×1014 ions/cm2) caused the formation of dislocation loops. In this case the growth of pits is similar to the case of simple annealing without bombardment.

Effect of ion-beam treatment on the cyclic life of alloy VT18U

The physicochemical state of the surface layers of specimens of alloy VT18U subjected to ion-beam (B+, N+, C+, Pd+, La+) and heat treatment is determined by methods of electron-Auger spectroscopy, X-ray structural analysis, exoelectron emission, and Faraday impedance. It is shown that the thickness of the ion-alloyed layer does not exceed 1 μm. Tests are carried out for specimens in the original and irradiated conditions for cyclic endurance at 500°C whose results indicate that it may be possible to increase their life by several factors by means of ion-beam treatment. Fracture surfaces are studied by electron fractography. It is established that the effectiveness of ion-alloying from the point of view of improving fatigue resistance is due to a combination of chemical and physical processes which occur in the thin surface layer with irradiation and heat treatment as a result of which there is a change in the mechanism of crack initiation (for ion-alloyed specimens the failure site is beneath the surface at a depth of 6.5–135 μm, and for original specimens it is at the surface).

Ion-beam-assisted coatings for corrosion protection studies

For corrosion protection, modified surfaces or coatings prepared by ion implantation or ion beam mixing often are not sufficient for technical long-term applications. The main problem, i.e. the shallowness of the films, can be overcome by ion-beam-assisted deposition which offers the positive effects of ion beam treatment, e.g. high adhesion, low porosity, and a low process temperature without thickness limitation. The corrosion protection behaviour of a number of coatings, e.g. boron, chromium and their nitrides, chromium oxide, silicon, hard carbon and aluminium, are discussed. The results demonstrate ion-beam-assisted deposition to be appropriate for producing adherent coatings which are well suited to long-term protection against corrosion, and partly also against tribological deterioration, even for technical rough surfaces.