Navegação Ciências Exatas e da Terra por Assunto "Difração de raios X"

Resultados 21-40 de 40

    • Spatial separation of vacancy and interstitial defects formed in Si by oxygen-ion irradiation at elevated temperature 

      Danilov, Iuri; Boudinov, Henri Ivanov; Souza, Joel Pereira de; Drozdov, Yu. N. (2005) [Artigo de periódico]
      A study of damage depth distribution in Si by elevated temperature O+-ion implantation was performed using three structures: (i) bulk Si, (ii) Si/SiO2 /bulk Si, and (iii) SiO2 /bulk Si. The samples were implanted at 250°C ...

    • Strain development and damage accumulation during neon ion implantation into silicon at elevated temperatures 

      Cima, Carlos Alberto; Boudinov, Henri Ivanov; Souza, Joel Pereira de; Suprun-Belevich, Yu.; Fichtner, Paulo Fernando Papaleo (2000) [Artigo de periódico]
      The development of mechanical strain and accumulation of damage in silicon single crystals implanted with Ne ions to doses in the range of 0.1–1.0 x1017 cm-² at temperatures from 200 to 600 °C were investigated employing ...

    • Structural and magnetic behavior of ar+-implanted co/pd multilayers : interfacial mixing 

      Schelp, Luiz Fernando; Carara, Marcos Andre; Viegas, Alexandre da Cas; Vasconcellos, Marcos Antonio Zen; Schmidt, Joao Edgar (1994) [Artigo de periódico]
      The magnetization behavior of Co/Pd multilayers has been analyzed as a function of the degree of interfacial mixing among the Co and Pd layers. Controlled atomic mixing was induced by low-dose and low-flux ion implantation ...

    • Structural and Mössbauer characterization of the ball-milled Fe/sub x/(Al/sub 2/O/sub 3)/sub 100-x/ system 

      Paesano Junior, Andrea; Matsuda, Célia Kimie; Cótica, Luiz Fernando; Medeiros, Suzana Nóbrega de; Cunha, Joao Batista Marimon da; Hallouche, Bachir; Silva, Selma Luiza (2004) [Artigo de periódico]
      Metal-oxide composites were synthesized by high-energy ball milling of metallic iron (α-Fe) and alumina (α-Al2O3) powders, varying the starting relative concentration and the milling time. The samples were characterized ...

    • Structural and spectroscopic investigation of the charge-ordered, short-range ordered, and disordered phases of the Co3O2BO3 ludwigite 

      Galdino, Carlos William; Freitas, Daniele; Medrano, Cynthia Paola Contreras; Sánchez, D. R.; Souza, Rodolfo Tartaglia; Rabello, L. P.; Mendonça, Alberto Aguiar; Ghivelder, Luis; Continentino, Mucio Amado; Zapata, Maximiliano Jesús Moreno; Pinheiro, Carlos Basílio; Azevedo, Gustavo de Medeiros; Rodríguez-Velamazán, J. A.; Garbarino, Gaston; Núñez-Regueiro, M.D.; Granado, E. (2021) [Artigo de periódico]
      Charge ordering is prone to occur in crystalline materials with mixed-valence ions. It is presumably accompanied by a structural phase transition, with possible exceptions in compounds that already present more than one ...

    • Structural change and heteroepitaxy induced by rapid thermal annealing of CaF/sub 2/ films on Si(111) 

      Mattoso Filho, Ney Pereira; Mosca Junior, Dante Homero; Schreiner, Wido Herwig; Mazzaro, Irineu; Teixeira, Sergio Ribeiro; Macedo, Waldemar A.A.; Martins, M.D. (1998) [Artigo de periódico]
      In this article we show that heteroepitaxial CaF2 films can be induced on Si~111! with a rapid thermal anneal. The change from preferentially oriented polycrystals to a single crystal with type- B epitaxy is visible by ...

    • Structural changes of fe precipitates in annealed fe-al/sub 2/o/sub 3/ films 

      Alves, Maria do Carmo Martins; Tolentino, Hélio Cesar Nogueira; Teixeira, Sergio Ribeiro; Flores, Wladimir Hernandez; Boff, Marco Aurelio Silveira; Casarin, Fabricio de Oliveira; Schmidt, Joao Edgar (1999) [Artigo de periódico]
      We report on the structural changes of Fe-AI203 films deposited - both co-evaporated and multilayered samples - at room temperature and subsequently annealed at 400"C during 5h. Our results suggest that the Fe precipitates ...

    • Structural characterization of the Co/sub 2/FeZ(Z=Al, Si, Ga, and Ge) Heusler compounds by x-ray diffraction and extended x-ray absorption fine structure spectroscopy 

      Balke, Benjamin; Wurmehl, Sabine; Fecher, Gerhard H.; Felser, Claudia; Alves, Maria do Carmo Martins; Bernardi, Fabiano; Morais, Jonder (2007) [Artigo de periódico]
      This work reports on the structure of Fe containing, Co2-based Heusler compounds that are suitable for magnetoelectronic applications. The compounds Co2FeZ where Z=Al, Si, Ga, and Ge were investigated using the x-ray ...

    • Structural, microstructural and magnetic characterization of the β-CoTe nanophase synthesized by a novel mechanochemical method 

      Malagutti, Marcelo Augusto; Ulbrich, K. F.; Paes, Vagner Zeizer Carvalho; Geshev, Julian Penkov; Campos, Carlos Eduardo Maduro de (2021) [Artigo de periódico]
      This work reports an unprecedented mechanochemistry synthesis of β-CoTe and its systematic characterization through X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), and magnetometry techniques. The ...

    • Structural modifications in FexCo1-x/Cu multilayers induced by ion irradiation 

      Graff, Ismael Leandro; Teixeira, Sergio Ribeiro; Amaral, Livio; Alves, Maria do Carmo Martins; Flores, Wladimir Hernandez (2004) [Artigo de periódico]
      The structural evolution of Fe30Co70 /Cu multilayers under ion irradiation is investigated in detail using x-ray techniques. The samples were irradiated with two different ions, 50 keV of He+ and 600 keV of Kr+, at room ...

    • Structure, microstructure and magnetic investigation of the hexagonal d-FeSe nanophase produced by mechanochemical synthesis 

      Ulbrich, K. F.; Paes, Vagner Zeizer Carvalho; Geshev, Julian Penkov; Campos, Carlos Eduardo Maduro de (2020) [Artigo de periódico]
      We present a systematic structural, microstructural and magnetic characterization of the hexagonal d-FeSe nanophase produced by a simple one-step mechanochemical synthesis route, by using conventional X-ray powder diffraction ...

    • A study of the structural, magnetic, and electrical properties of Ba1-xNaxCoO3 compounds (x = 0.25, 0.5, 0.75) 

      Estrada-Rodríguez, Carlos A.; Lopes, Lutiene Fernandes; Lopes, Rovan Fernandes; Mesquita, Fabiano; Turatti, Águeda Maria; Pimentel Junior, Jorge Luiz; Sandoval-Gutiérrez, Santiago; Parra Vargas, Carlos Arturo (2021) [Artigo de periódico]
      Cobaltite-like materials having metal-insulator transitions are relevant in the consumer electronics market. In this work, we present the structural, magnetic, and electrical properties of Ba1-xNaxCoO3(with x= 0.25, 0.5, ...

    • Surface morphology of spray-dried nanoparticle-coated microparticles designed as an oral drug delivery system 

      Beck, Ruy Carlos Ruver; Lionzo, Maria Ismenia Zulian; Costa, Tania Maria Haas; Benvenutti, Edilson Valmir; Ré, Maria Inês; Gallas, Marcia Russman; Pohlmann, Adriana Raffin; Guterres, Silvia Stanisçuaski (2008) [Artigo de periódico]
      This paper was devoted to studying the influence of coating material (nanocapsules or nanospheres), drug model (diclofenac, acid or salt) and method of preparation on the morphological characteristics of nanoparticle-coated ...

    • The epitaxial growth of evaporated cu/caf2 bilayers on si(111) 

      Mattoso Filho, Ney Pereira; Mosca Junior, Dante Homero; Mazzaro, Irineu; Teixeira, Sergio Ribeiro; Schreiner, Wido Herwig (1995) [Artigo de periódico]
      Successful and unexpected epitaxial growth of Cu/CaF2, bilayers on hydrogen terminated Si(111) wafers by thermal evaporation is reported. The bilayers were characterized with conventional x-ray diffraction experiments, ...

    • The influence of nitrogen to hydrogen ratio and temperature on thickness and phase composition in plasma nitrided Ti-6Al-4V 

      Lima, Saulo Cordeiro; Hinrichs, Ruth; Vasconcellos, Marcos Antonio Zen (2019) [Artigo de periódico]
      Ti-6Al-4V was plasma nitrided using several N2/H2 ratios and substrate temperatures. In order to investigate the combined influence of these parameters on phase compositionand thickness of the coatings,the phases in the ...

    • Tuning anatase-rutile phase transition temperature : TiO2/SiO2 nanoparticles applied in dye-sensitized solar cells 

      Cardoso, Billy Nunes; Kohlrausch, Emerson Cristofer; Laranjo, Marina Teixeira; Benvenutti, Edilson Valmir; Balzaretti, Naira Maria; Arenas, Leliz Ticona; Santos, Marcos José Leite; Costa, Tania Maria Haas (2019) [Artigo de periódico]
      TiO2/SiO2 nanoparticles with 3, 5, and 10 molar percent of silica, were synthesized by hydrothermal method and characterized by SEM, TEM, N2 adsorption-desorption isotherms, X-ray diffraction, and Raman and UV-Vis spectroscopy. ...

    • Ultrafast trapping times in ion implanted InP 

      Carmody, Christine; Boudinov, Henri Ivanov; Tan, Hoe H.; Jagadish, Chenupati; Lederer, Max J.; Koley, Vesselin; Luther-Davies, B.; Dao, L.V.; Gal, Michael (2002) [Artigo de periódico]
      As+ and P+ implantation was performed on semi-insulating (SI) and p-type InP samples for the purpose of creating a material suitable for ultrafast optoelectronic applications. SI InP samples were implanted with a dose of ...

    • Unraveling structural and compositional information in 3D FinFET electronic devices 

      Trombini, Henrique; Marmitt, Gabriel Guterres; Vellame, Igor Alencar; Baptista, Daniel Lorscheitter; Reboh, Shay; Mazen, Frédéric; Pinheiro, Rafael Bortolin; Sanchez, Dario Ferreira; Senna, Carlos Alberto; Archanjo, Braulio Soares; Achete, Carlos A.; Grande, Pedro Luis (2019) [Artigo de periódico]
      Non-planar Fin Field Effect Transistors (FinFET) are already present in modern devices. The evolution from the well-established 2D planar technology to the design of 3D nanostructures rose new fabrication processes, but a ...

    • Valence and delocalization of yb in the Chevrel-phase YbMo 6 S 8 

      Jorgensen, James D.; Hinks, D.J.; Noakes, D.R.; Viccaro, Patsy James; Shenoy, G.K. (1983) [Artigo de periódico]
      Mãssbauer isomer-shift measurements show that Yb is divalent in YbMo6Sg. The asymmetry of the Yb thermal vibration at 4.2 K obtained from the Goldanskii-Karyagin effect is much smaller than that obtained from a Rietveld ...

    • X-ray-absorption spectroscopy and x-ray diffraction in discontinuous Co/sub x/Fe/sub 1-x//Ag multilayers 

      Flores, Wladimir Hernandez; Teixeira, Sergio Ribeiro; Cunha, Joao Batista Marimon da; Alves, Maria do Carmo Martins; Tolentino, Hélio Cesar Nogueira; Traverse, Agnes (2000) [Artigo de periódico]
      This paper reports on the structural properties of CoxFe12x /Ag discontinuous multilayers with x 50, 0.3, 0.7, and 1. The evolution of the structural properties has been investigated by x-ray diffraction and x-ray-absorption ...