I. B. Khaibullin

Depth distribution of Cu, Ag and Au ions implanted at low energy into insulators

The binary collision approximation based on the dynamic computer code DYNA has been employed to simulate the implantation of metal ions (Cu, Ag and Au) into silica, soda‐lime silicate glass and aluminium oxide. Dependencies of elemental concentrations for low ion energies of 30, 60 and 100 keV have been obtained at doses of 0.1, 0.3, 0.6 and 1 10 16 ion/cm 2 . Target sputtering and a change of the near-surface layer composition due to cascade atom mixing is considered. Dynamic formation of non-symmetrical depth distributions of implanted ions during irradiation was computed and discussions related to the influence of implantation conditions on the shape of the depth distribution are presented. ” 2000 Elsevier Science B.V. All rights reserved.

Formation of metal-polymer composites by ion implantation

Abstract Silver nanoparticles have been synthesized by ion implantation at 30 keV into polymethyl-methacrylate at doses from 3.1 × 1015 to 7.5 × 1016 ion cm−2 and a beam current 4 μA cm−2 at room temperature. Transmission electron microscopy was used to determine the structure of the silver-polymer systems obtained. It was observed that in the prepared samples, spherical metal particles with sizes smaller than 12 nm were fabricated. For characterization of the optical response of the composites, transmittance spectroscopy was employed. The formation of the silver nanoparticles leads to an increase of the optical absorption bends at the plasma wavelength in the visible range, where the spectral position of the transmittance minimum depends on the implantation conditions. It was observed that the intensity of the absorption is very weak in spite of the large quantity of silver particles existing in the polymer medium; the factors influencing the optical data are discussed.

Structure and photoluminescent properties of SiC layers on Si, synthesized by pulsed ion-beam treatment

Abstract We report the formation of the continuous β-SiC layers on Si by means of C + implantation into Si followed by pulsed ion-beam treatment (C + , 300 keV, 50 ns). Transmission electron microscopy and electron diffraction indicate the formation of a polycrystalline β-SiC layers with a grain size of up to 100 nm. Porous SiC/Si structures were prepared by anodization and were studied by photoluminescence (PL) at room temperature. Three PL bands were observed at 460, 520 and 615 nm and were ascribed to the SiC nanocrystals, C-rich clusters and Si nanocrystals, respectively. The time constant τ =40 ns was deduced from time-resolved PL measurements. It is close to the value for direct band gap semiconductors and is shorter nearly by 3 orders of magnitude than that for porous Si.

Ion Synthesis of Colloidal Silver Nanoclusters in the Organic Substrate

High-dose ion implantation was used to create silver metallic grains in the epoxy resins The structure and optical properties of Ag/organic systems were investigated by transmission electron microscopy and absorption UV-visible spectroscopy, It was established that silver implantation into the organic substrate produced colloidal nanoclusters in the near-surface region, whose average size and size distribution were function of dose value. The silver nanoclusters give rise to optical absorption at the plasmon wavelength. and maximum absorption was shown to be correlated with filling factors. The d.c. resistivities of irradiated samples were measured in temperature range from 5 to 300 K The observed exp(T 0 /T) n behaviour of resistivity indicated that synthesized metal particles are separated.

SYNTHESIS OF METAL/POLYMER COMPOSITE FILMS BY IMPLANTATION OF FE AND AG IONS IN VISCOUS AND SOLID STATE SILICONE SUBSTRATES

Abstract We investigated a process of metal phase synthesis in a polymer by high-dose implantation of metal ions in silicone substrates at constant current density. The samples were obtained by implantation of 40 keV Fe + and 30 keV Ag + ions in both viscous (at the moment of implantation) and solid state silicone polymers. The structural and physical properties of the irradiated polymers were investigated by TEM, magnetic resonance and absorption UV–VIS spectroscopy. The strong influence of the relaxation state of the silicone target on the metal phase growth, morphology and sizes of iron and silver nanostructures, as well as the magnetic and optical properties of the synthesized metal/polymer composite films are shown experimentally.

Coloration of natural beryl by iron ion implantation

AbstractNaturalcolorlesscrystalsofUralberylwereimplantedatroomtemperaturewith40keVFe þ ionswithfluencesinthe range of 0.5–1.5 10 17 ion/cm 2 . As-implanted samples show dark-grey tone due to radiation damage of berylcrystal.Subsequentthermalannealingofirradiatedcrystalsinoxygenat600 Cfor30minresultsinthecolorchange,toyellowishoryellow–orangetoneswithgoldenluster,dependingonvalueofironfluence.Thenatureofberylcol-oration was studied by optical absorption, Moossbauer and Rutherford backscattering (RBS) spectroscopes. It was€establishedthatthethermaltreatmentofiron-irradiatedberylleadtoinwarddiffusiveredistributionofironions.Anappearanceofopticalabsorptionbandsconnectedwithcharge-transfersO 2 !Fe 3þVI andO 2 !Fe 2þIV ,Fe 3þIV determinetheyellowtoneincoloredberyls.MostofimplantedironionsarefoundedinbothtetrahedralFe 2þIV andoctahedralFe 3þVI siteswheretheymaysubstituteberylliumandaluminumhostionsbyisomorphicway. 2003ElsevierScienceB.V.Allrightsreserved. PACS:61.72.Ww;61.82.Ms;91.60.Mk;76.80.þyKeywords:Ion implantation;Beryl;Opticalabsorption;M€oossbauerspectroscopy

Structural and magnetic properties of iron and cobalt implanted silicone polymers

Abstract 40 keV Fe+ and Co+ ions were implanted in both viscous and solid silicone substrates at doses of (0.1–1.8)×1017 ions/cm2 and an ion current density of 4 μA/cm2. The microstructure and magnetic properties of the Fe- and Co-implanted silicone layers were then investigated as a function of the initial relaxation state (viscosity) of the polymer target. TEM investigations showed that granular Fe and Co films consisting of fine isolated particles are synthesized in the solid substrates at doses higher than 0.3×1017 ions/cm2. At the same dose multiparticle iron agglomerates and closely packed large Co particles with a mean size of 200 nm are formed in substrates implanted in the viscous state. FMR studies revealed essential differences in the magnetic properties of the metal films synthesized at different viscosity of the silicone substrate. The temperature dependence of the FMR spectra and the dose dependence of the effective magnetization of the synthesized films were studied.

Kinetics of silver nanoparticle formation in a viscous-flow polymer

Abstract The vacuum deposition of silver atoms onto viscous-flow epoxy has been performed over a wide range of substrate viscosities from 20 to 200 Pa · s. The possibility of synthesising small (1.5–2.5 nm) metal particles in the polymer volume at a depth of several tens of nm is demonstrated. The relationship between particle sizes, the depth of their placement and substrate viscosity is determined by TEM measurements made normal and parallel to the substrate surface. Samples prepared at different deposition times of silver atoms onto a 20 Pa · s substrate were used to investigate the subsurface particle growth kinetics. The fundamental stages of submerged silver dispersion film formation are established by experiments and computer simulation of the absorption spectra of metal/polymer composites. Some numerical estimates of the process of nanoparticle nucleation and growth are presented.

Depth profiles of metal ions implanted in dielectrics at low energies

The depth profiles of Cu+, Ag+, and Au+ ions implanted into amorphous dielectric SiO2, Al2O3, and soda-lime silicate glass (SLSG) are simulated by the DYNA program. The algorithm follows projectile-ion-substrate-atom pair collisions giving rise to a dynamic variation in the phase composition in the surface layer of the irradiated material and takes into account surface sputtering. Ion implantation up to doses of ≤1016 ion/cm2 at low ion energies of 30, 60, and 100 keV is considered. The measured dynamic variation of the depth profiles of implanted ions as a function of the dose is compared with the standard statistical distribution calculated by the TRIM algorithm.

Effect of ion current density on the phase composition of ion beam synthesized iron silicides in Si (100)

Abstract Phase composition of Fe+ implanted in Si(100) at elevated temperatures was investigated over a wide range of ion current densities. Phases and texture were determined by glancing angle XRD. Both FeSi and β-FeSi2 phases were observed. The phase composition of the synthesized layers was found to be strongly affected by ion current density. The increase of the ion current density at an implantation temperature of 450°C leads to a rise in relative content of β-FeSi2. This effect is explained by the spreading of the Fe profile. Such changes of the profile are the result of the radiation enhanced diffusion during implantation.