Electrical Contacts
Mostrando 13-24 de 39 artigos, teses e dissertações.
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13. Micro e nanofabricação (fabricação de contatos eletricos) por feixe de ions focalizados / Micro and nano (manufacture of electrical contacts) with focused ion beam
Nanoscale science and technology is a young and burgeoning field that encompasses nearly every discipline of science and engineering, the rapid growth of the field in the past decades has been enable by the sustained advances in the fabrication and characterization of materials. This work presents the hybrid process for fabrication of micro and nanocontacts,
Publicado em: 2007
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14. Nanomanipulation and characterization of individual nano-objects for in situ experiments of electron microscopy / Nanomanipulação e caracterização de nano-objetos individuais por experimentos in situ de microscopia eletronica
It is expected that, in the future, high-technology devices should be based on new and unexpected physical and chemical properties of nanometric objects. Many applications require nano-objects to be selectively positioned at well-defined positions of a device. However, the well-established methods of physical manipulation used in the macroscopic scale are no
Publicado em: 2007
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15. Electrical and morphological properties of low resistivity Mo thin films prepared by magnetron sputtering
Mo thin films have been deposited using a DC magnetron sputtering system with an S-gun configuration electrode and characterized electrically and morphologically. The influence of the sputtering gas pressure and glow discharge (GD) power, on the electrical resistivity of Mo thin films and on the contact resistivity of Mo to Cu(In,Ga)Se2 (CIGS) films was dete
Brazilian Journal of Physics. Publicado em: 2006-09
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16. Caracterização elétrica de contatos rasos de siliceto de níquel sobre junções N+P. / Electrical characterization of nickel-silicide shallow contacts on N+P junctions.
This work presents the fabrication and electrical characterization of Al/Ti/Ni(Pt)Si contacts having the nickel monosilicide formed from Ni(30nm)/Pt(1.5nm)/Si structure on shallow N+P junctions with about 0.2 ìm of depth. The diodes? electrical behavior achieved at the best process was considered good, with the following average and standard deviations: are
Publicado em: 2006
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17. Estudo de interferência de elétrons em dispositivos mesoscópicos no limite Hall quântico
In this work we introduce the basic concepts required to understand how electronic interferometers work. The interferometers are semiconductor devices based in GaAs/AlGaAs heterojunctions where a high mobility two-dimensional electron gas is formed. The electron gas is confined in a small region of dimension comparable to its Fermi wavelength. In a high magn
Publicado em: 2006
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18. ProduÃÃo de heterojunÃÃes de polianilina/silÃcio e nanofibras de polianilina para aplicaÃÃes em dispositivos hÃbridos
In this work we develop the methodology for the synthesis and fabrication of Polyaniline (PANI) â Silicon (Si) heterojunctions, with great potential for technological applications as sensors in different areas such as optics, ionizing radiation and gas detection. Besides, we were able to implement the electrospinnin technique with the goal of producing poly
Publicado em: 2006
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19. AC electrical conductivity of Cr-doped polyaniline/poly(vinyl alcohol) blends
Polyaniline (PANI) and their charge transfer complexes are engineering materials that continue to attract considerable attention from engineers due to their unique electrochemical behavior, environmental stability and high degree of processability. Extensive works on the preparation of electrically conductive PANI blends containing a polymeric matrix having
Brazilian Journal of Physics. Publicado em: 2004-06
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20. Gap junctions in cells of the immune system: structure, regulation and possible functional roles
Gap junction channels are sites of cytoplasmic communication between contacting cells. In vertebrates, they consist of protein subunits denoted connexins (Cxs) which are encoded by a gene family. According to their Cx composition, gap junction channels show different gating and permeability properties that define which ions and small molecules permeate them.
Brazilian Journal of Medical and Biological Research. Publicado em: 2000-04
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21. Polyaniline: synthesis, films, doping and DC conduction / Polianilina: síntese, filmes, dopagem e condução DC
In this work, we accomplished a study of the dependence of the dc electrical conductivity ( ), with the doping level (time of immersion of the film into the hydrochloric acid - 0 t 6 hours), temperature (80 T 300K) and electric field (E) in polyaniline thin films. The electric contacts to the samples were obtained using gold deposited in both faces and the m
Publicado em: 1999
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22. Viabilidade da utilização da liga Sn - Ni65 - 35 eletrodepositada em contatos eletricos
The possibility of tin-nickel alloy coating application in electric contacts used in low voltage-Iow current through the study of its properties is presented. The samples were prepared with a commercial bath and the proportion of the elements in the alloy were 65% of tin and 35% of nickel in weight. The alloy composition and structure were analised by X Rays
Publicado em: 1995
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23. Study of the transport and storage properties of electric charges in Teflon FEP films. / Estudo das propriedades de transporte e armazenamento de cargas elétricas em filmes de Teflon FEP.
The Heat Pulse and TSC (Thermo-Stimulated-Current) in open circuit techniques were used to study the transport and storage of injected charge in Teflon FEP films. Using these techniques it was possible to follow the evolution of the injected charge inside the samples. Virgin samples (as received), previously annealed samples and previously ionic bombarded sa
Publicado em: 1986
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24. Chaves eletricas a semicondutor controladas por pulsos laser de picosegundos
In this work we have studied the construction of ultra-fast electrical switches activated by ultrashort laser pulses. Such devices, built based on high-resistivity semiconductors, transform the energy of ultra short light pulses in electrical signals. These signals have rise time and pulse width of the order of pico-seconds. Parameters concerning the constru
Publicado em: 1984