Monodisperse 4 nm FePt magnetic nanoparticles were synthesized by superhydride reduction of FeCl2 and Pt(acac)2 at high temperature, thin assemblies with controlled thickness formed via polymer mediated self-assembly. Adding (LiBEt3H) to the phenyl ether solution in presence oleic acid, oleylamine, 1,2-hexadecanediol 200 °C, followed refluxing 263 led monodisperse nanoparticles. The initial molar ratio metal precursors was retained during synthesis, final composition particles readily tuned....

We present a simple polymer-mediated process of assembling magnetic FePt nanoparticles on solid substrate. Alternatively absorbing the PEI molecule and HO-terminated surface leads to smooth nanoparticle assembly with controlled thickness dimension. Magnetic measurements show that thermally annealed as thin three layers is ferromagnetic. The magnetization direction this readily laser-assisted writing. reported can be applied various substrates, nanoparticles, functional macromolecules will...

The formation of NiSi films from the reaction Ni2Si with (100) and (111) silicon substrates was found to be controlled by a lattice diffusion process an activation energy 1.70 eV. In order correlate kinetic information obtained Rutherford backscattering x-ray diffraction data, ‘‘standard’’ powder patterns for both have been established. existence metastable hexagonal form has confirmed. Observations on confirm previous investigations. at work during is discussed in terms crystalline...

Previously, ion-beam irradiation has been shown to locally alter the magnetic properties of thin Co/Pt multilayer films. In this work, we have used through a silicon stencil mask having 1-μm-diam holes pattern film. Regularly spaced micrometer-sized regions magnetically altered material produced over areas square millimeter in multilayers. These structures observed by force microscopy. The patterning technique is demonstrated with mask–sample spacing as large 0.5 mm. addition, smaller...

Shallow (<0.2 μm) n+ layers in Si with high conductivity (<40 Ω/⧠) have been formed by high-dose (2×1016 cm−2) As implants. Experimental observations of distributions and carrier concentrations are successfully simulated a computer program which accounts for both the concentration dependent diffusion clustering effects. Reduction electrical carriers implanted during moderate temperature (∼800 ° C) heat treatments is readily explained kinetics clustering. Physical limitations on...

Single-crystal silicon samples have been made disordered by irradiation with pulses from a frequency-quadrupled neodynium-doped-yttrium-aluminum-garnet laser ${10}^{\ensuremath{-}8}$-s pulse length. We studied the resulting amorphous layer transmission electron microscopy and He-ion backscattering. Irradiation longer-wavelength restored to its original crystalline state. This order-disorder laser-radiation-induced transition is repeatable.

The formation of silicides from thin films the rare-earth (or related) elements Y, Tb, and Er, on both (100) (111) Si substrates, has been investigated simultaneously with backscattering x-ray diffraction. silicon-rich compounds type R-ESi2−n form almost directly no, or only poorly distinct other at temperatures about 300 to 500 °C. For all three metals, reactions require some 100 °C higher than Si, a difference in behavior which is quite important considering relatively low reaction...

A new technique is described in detail which can be used to profile boron impurities almost any substrate a depth of few microns. It uses the reaction 10B (n,4He)7Li convert atoms monoenergetic α particles are detected after they leave target. The sensitive at levels as low 3 ppm, with resolution ±20/nm for silicon. deconvoluting this type experimental data detail. Methods presented eliminate problem spurious oscillations deconvoluted data. Examples shown analyze various distributions

A marker study of the silicides (and germanides) rare-earth elements obtained from metallic thin films on Si Ge) substrates indicates that Si(and atoms constitute dominant diffusing species during formation these two types compounds. Rutherford backscattering is used to distinguish between pairs having different atomic weights but very similar with respect their chemical and metallurgical behavior. An experiment conducted diffusion bilayer sample Ge-Tb confirms results bilayers type Y-Tb (or...

The formation of iridium silicides from the interaction films with single-crystal silicon substrates has been studied 350 to 1000 °C. Three distinct phases, IrSi, IrSi1.75(?), and IrSi3, were identified. Different modes observed investigated. IrSi IrSi1.75 form in layers parallel substrate at temperatures 900 growth IrSi3 nuclei that spread laterally occurs about °C, where possible kinetics systematically studies.

The utilization of WSi2 thin films as gate electrodes in field-effect transistors depends on the ability this material to form a continuous electrically insulating SiO2 overlayer. In steam oxidation deposited polysilicon, forms surface by means rapid diffusion Si through which appears case be quite inert. During initial stages SiO2, removal from silicide (to SiO2) apparently leads formation free W, rather than anticipated tungsten-rich W3Si3.

Adhesion of Cu to Teflon has been studied by depositing with and without a presputtering prior the deposition. Without presputtering, weak adhesion is observed, value 1 g/mm, which fails scotch tape test. With using 500 eV Ar+ ions, rapidly increases, becoming evident after sputtering 10 s, reaches maximal increases 50 times at longer times. All films deposited show strong adhesion, can only be removed forceful scratching sharp tools. The was shown change both surface morphology Teflon,...

The first use of an intense pulsed ion beam to anneal ion-implanted semiconductors is reported. Helium channeling shows that a single 80-ns pulse 200-keV H+ ions at ∼100 A/cm2 produced good crystallinity in silicon implanted with 1014 As/cm2 100 keV.

Co/Pt multilayers can exhibit large perpendicular anisotropies and coercivities that are very sensitive to the quality of interfaces. We have characterized dependence coercivity on irradiation with various ion species (He+, Ar+, Ga+), energies (20 keV–2 MeV), doses (1011–1017 ions/cm2), in order understand better nature structural changes responsible for magnetic changes. find that, general, system is much more than expected basis a nearest-neighbor coupling model simple ballistic ion-beam mixing.

An analysis has been made to extract the concentration profiles of impurities in upper two microns a substrate surface. The technique used is nuclear backscattering. Since stopping power materials nonlinear with energy, detailed calculations are necessary unfold impurity distributions. were tested by analyzing arsenic silicon. Four MeV helium was as projectile. Because reaction 28Si(α, α)28Si at 2–4 occurs region many energy levels 32S, fitting cross sections from an optical-model...

Co/Pt multilayer films with perpendicular magnetic anisotropy and large out-of-plane coercivities of 3.9–8.5 kOe have been found to undergo a spin reorientation transition from in-plane upon irradiation 700 keV nitrogen ions. X-ray reflectivity experiments show that the structure gets progressively disrupted increasing ion dose, providing direct evidence for local atomic displacements at interfaces. This effectively destroys interface anisotropy, which was varied by about factor 2, between...

We have used ion beam irradiation through a silicon stencil mask to alter the magnetic properties of Co/Pt multilayer and FePt chemically-ordered superlattice films. In both systems, disorders as-grown films which results in reduction anisotropy. Regularly spaced micrometer-sized regions magnetically altered material been produced over areas square millimeter. These structures observed by force microscopy. By stepping during irradiation, features at twice spatial frequency holes produced....

The reactions of ruthenium and osmium thin films with their silicon substrates lead to the formation following phases: isomorphous Ru2Si3 Os2Si3, OsSi2. forms by a diffusion controlled mechanism from approximately 450 525 °C; activation energy is 1.8 eV. Os2Si3 grows same process as Ru2Si3, but at slightly higher temperatures (for equivalent rates). OsSi2 about 750 °C nucleation mechanism. With an alloy containing 33 at.% rhodium, one obtains RuSi, which 2.4 eV 400 475 °C, Ru2Si3. In case...