Browsing Exact and Earth Sciences by Subject "Implantação de íons"

Now showing items 21-40 of 68

    • Impact-parameter dependence of the electronic energy loss of fast ions 

      Grande, Pedro Luis; Schiwietz, Gregor (1998) [Journal article]
      In this work we describe a model for the electronic energy loss of bare ions at high velocities. Starting from first-order perturbation theory we propose a simple formula to calculate the impact-parameter dependence of the ...

    • Implanted boron depth profiles in the az111 photoresist 

      Guimaraes, Renato Bastos; Amaral, Livio; Behar, Moni; Fichtner, Paulo Fernando Papaleo; Zawislak, Fernando Claudio (1988) [Journal article]
      The isotope 1OB has been implanted into the photoresist AZll1 in the 30–150 keV energy range. The corresponding depth profiles have been analyzed using the 1OB(n,a) 7 Li reaction. At 60 keV, the profile changes from a ...

    • Improved calculations of the electronic and nuclear energy loss for light ions penetrating H and he targets at intermediate velocities 

      Grande, Pedro Luis; Schiwietz, Gregor (1994) [Journal article]
      A review is given on the use of the coupled-channel method to calculate the electronic and niuclear energy loss of ions penetrating the matter. This first principie calculation based on an expansion of the time dependent ...

    • Impurity resistivity of the double-donor system Si:P,Bi 

      Silva, Antonio Ferreira da; Sernelius, Bo E.; Souza, Joel Pereira de; Boudinov, Henri Ivanov; Zheng, Hairong; Sarachik, M.P. (1999) [Journal article]
      The electrical resistivity of the shallow double-donor system Si:P,Bi, prepared by ion implantation, was investigated in the temperature range from 1.7 to 300 K. Good agreement was obtained between the measured resistivities ...

    • Influence of nuclear track potentials in insulators on the emission of target auger electrons 

      Schiwietz, Gregor; Grande, Pedro Luis; Skogvall, B.; Biersack, J.P.; Kohrbruck, R.; Sommer, K.; Schmoldt, A.; Goppelt, P.; Kadar, I.; Ricz, S.; Stettner, U. (1992) [Journal article]
      The angle, energy, and fluence dependence of electron emission following the interaction of normally incident 100-MeV Ne⁹⁺ ions with thin polypropylene foils and 170-MeV Ne⁷⁺ projectiles with Mylar foils has been investigated ...

    • Influence of the implantation and annealing parameters on the photoluminescence produced by Si hot implantation 

      Sias, Uilson Schwantz; Behar, Moni; Boudinov, Henri Ivanov; Moreira, Eduardo Ceretta (2007) [Journal article]

    • Intermetallic phases formed during tin implantation into iron and steels 

      Dionisio, Paulo Henrique; Barros Junior, Bernardo A.S. de; Baumvol, Israel Jacob Rabin (1984) [Journal article]
      The surface layers of pure iron, high-carbon steel and stainless steel, ion implanted with 1 X 1017 Sn+ cm-² , have been characterized by means of 119Sn conversion electrons Mossbauer scattering. The intermetallic phases ...

    • Ion beam synthesis of cubic FeSi2 

      Desimoni, Judith; Bernas, H.; Behar, Moni; Lin, X.W.; Washburn, J.; Liliental-Weber, Zuzanna (1993) [Journal article]
      Cubic FeSi, precipitates were synthesized in Si ( 100) by room-temperature Fe ion implantation followed by Si 500 keV ion beam induced epitaxial crystallization at 320 “C!. High resolution electron microscopy and Rutherford ...

    • Ion radiation induced diffusion of xe implanted into a polymer film 

      Kaschny, Jorge Ricardo de Araujo; Amaral, Livio; Behar, Moni; Fink, Dietmar (1992) [Journal article]
      In the present work, we have studied the most important parameters which can influence the radiation induced diffusion mechanism of Xe ions implanted into a photoresist film. With this aim, we have Ar post-bombarded the ...

    • Iron nitride and carbonitride phases in a nitrogen implanted carbon steel 

      Santos, Carlos Alberto dos; Barros Junior, Bernardo A.S. de; Souza, Joel Pereira de; Baumvol, Israel Jacob Rabin (1982) [Journal article]
      Iron nitride and carbonitride phases formed during nitrogen implantation and subsequent thermal annealing of a medium-carbon steel are investigated by means of conversion electron Mossbauer scattering. The results are ...

    • Isotopic substitution of N, O, and Si in the thermal oxidation of nitrogen-deposited silicon 

      Baumvol, Israel Jacob Rabin; Salgado, Tania Denise Miskinis; Stedile, Fernanda Chiarello; Radtke, Claudio; Krug, Cristiano (1999) [Journal article]
      Nitrogen was deposited on the surface of Si~100! wafers by ion implantation at a very low energy (approximately 20 eV), at fluences between 1 and 1031014 cm22. The samples were thermally oxidized in dry O2 at temperatures ...

    • Low-temperature ion-induced epitaxial growth of alfa-FeSi2 and cubic FeSi2 in Si 

      Lin, X.W.; Behar, Moni; Desimoni, Judith; Bernas, H.; Washburn, J.; Liliental-Weber, Zuzanna (1993) [Journal article]
      Ion-beam-induced epitaxial crystallization of amorphous Si implanted with Fe to 18 at. % peak concentration was studied. The structure of the specimen was characterized using transmission electron microscopy and Rutherford ...

    • Low-temperature iron-nitride phase transformations induced by ion bombardment 

      Moreira, Eduardo Ceretta; Amaral, Livio; Behar, Moni; Foerster, Carlos Eugenio (1996) [Journal article]
      We show that for the Fe–N system the combined use of ion irradiation and thermal annealing can lower the temperature for a given phase transformation. By Ar bombarding N-implanted Fe samples at 250 and 300 °C, we have ...

    • Magnetoresistance in rf-sputtered(nife/cu/co/cu) spin-valve multilayers 

      Lottis, Daniel Kurt; Fert, Albert R.; Morel, Robert; Pereira, Luis Gustavo; Jacquet, J.C.; Galtier, P.; Coutellier, J.M.; Valet, Tierry (1993) [Journal article]
      A study of the vtiation of the magnetoresistancein (Ni80Fe20/Cu/Co/Cu) multilayers with the thicknesses tNiFe, tcO, and &;cu of each type of component layer has been performed. The magnetoresistance (MR), which at 4 .2 K ...

    • Mechanism for enhancement of electrical activation of silicon in GaAs by aluminum co-implantation 

      Souza, Joel Pereira de; Sadana, Devendra K. (1993) [Journal article]
      A pronounced enhancement in the electrical activation of implanted Si in GaAs is demonstrated by co-implantation of Al. The maximum enhancement ( x 2) occurs when the Si distribution is shallow, there is a separation between ...

    • Metastable acceptor centers in boron implanted silicon 

      Souza, Joel Pereira de; Boudinov, Henri Ivanov (1995) [Journal article]
      The evolution of the electrical activation with the annealing time in B1 implanted (5.0 31014 cm22, 50 keV! Si was studied as a function of the annealing temperature. Electrical activation yields of 15%–30% were observed ...

    • Mossbauer study of hydrogenated amorphous germanium-tin thin-film alloys 

      Dionisio, Paulo Henrique; Baumvol, Israel Jacob Rabin; Chambouleyron, I.; Barrio, R.A. (1989) [Journal article]
      This work reports on the structure of defects around Sn atoms in amorphous germanium-tin alloys deposited by the rf sputtering of compound targets, The influence of atomic hydrogen on the structure of such defects is ...

    • Nitrogen implantation into amorphous carbon films: sims and positron annihilation analyses 

      Freire Junior, Fernando Leite; Franceschini, Dante F.; Achete, Carlos A.; Baumvol, Israel Jacob Rabin; Brusa, R.S.; Mariotto, Gino; Canteri, R. (1996) [Journal article]
      Hard amorphous hydrogenated carbon films deposited by self-bias glow discharge were implanted at room temperature with 70 keV-nitrogen ions at fluences between 2.0 and 9.0 x 10 16 N/cm2. The implantation energy was chosen ...

    • Nonperturbative stopping-power calculation for bare and neutral hydrogen incident on he 

      Grande, Pedro Luis; Schiwietz, Gregor (1993) [Journal article]
      The electronic stopping power of hydrogen beams penetrating He gas has been calculated by solving the time-dependent Schrõdinger equation. Special attention has been given to low incident energies where capture and loss ...

    • On the behavior of deuterium in ultrathin SiO2 films upon thermal annealing 

      Baumvol, Israel Jacob Rabin; Gusev, Evgeni P.; Stedile, Fernanda Chiarello; Freire Junior, Fernando Lazaro; Green, Martin L.; Brasen, D. (1998) [Journal article]
      Following the observation of the large isotopic effect in D2 passivated gate dielectrics @J. Lyding, K. Hess, and I. C. Kizilyalli, Appl. Phys. Lett. 68, 2526 ~1996!#, we studied the behavior of deuterium in ultrathin SiO2 ...