Thin Titanium Oxide Films Obtained By Rtp And By Sputtering

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this paper, two methods to obtain titanium oxide (TiO2) thin films are compared. In the first method metallic titanium (Ti) is deposited by sputtering and then oxidized by rapid thermal process (RTP) in an oxygen atmosphere to form the TiO2 thin films. The second method consists in TiO2 deposition by reactive sputtering. Structural characterization of the prepared samples shows the rutile crystal structure for both films, but TiO2 thin film deposited by sputtering also presented anatase crystal structure. Capacitors were fabricated and the electrical characterization of TiO2 films realized in order to determine which method forms the best dielectric film, defined by high dielectric constant value (high-k), lower charge density (Q0/q) and flat-band voltage (VFB) around -0.9V.FAPESP; São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Bunjongpru, W., Sungthong, A., Porntheeraphat, S., Rayanasukha, Y., Pankiew, A., Jeamsaksiri, W., Srisuwan, A., Nukeaw, J., Very low drift and high sensitivity of nanocrystal-TiO2 sensing membrane on pH-ISFET fabricated by CMOS compatible process (2013) Appl. Surf Sci., 267, pp. 206-211. , FebChou, J.-C., Yang, H.-Y., Chen, C.-W., Glucose biosensor of ruthenium-doped TiO2 sensing electrode by co-sputtering system (2010) Microelectron. Reliab., 50 (5), pp. 753-756. , MayBarros, A.D., (2013) Developement of TiOx and ZnO Thin Films for ISFET and SAW Devices, , PhD Thesis, School of Electrical and Compuer Engineering, University of Camp in asSouza, J.F., Moreira, M.A., Doi, I., Diniz, A.I., Tatsch, P.J., Gonçalves, J.L., Preparation and characterization of high-k aluminium nitride (A1N) thin film for sensor and integrated circuits applications (2012) Phys. Status Solidi, 9 (6), pp. 1454-1457. , JunOkuya, M., Nakade, K., Kaneko, S., Porous TiO2 thin films synthesized by a spray pyrolysis deposition (SPD) technique and their application to dye-sensitized solar cells (2002) Solar Energy Materials & Solar Cells, 70, pp. 425-435Oja, I., Chemical solution deposition of thin TiO2 -anatase films for dielectric applications (2004) Materials Ins Electronics, 5, pp. 341-344Yu, J., Zhao, X., Zhao, Q., Photocatalytic activity of nanometer TiO2 thin films prepared by the sol - gel method (2001) Materials Chemistry and Physsics, 69, pp. 25-29Barros, A.D., Albertin, K.F., Miyoshi, J., Doi, I., Diniz, J.A., Thin titanium oxide films deposited by e-beam evaporation with additional rapid thermal oxidation and annealing for ISFET applications (2010) Microelectron. Eng., 87 (3), pp. 443-446. , MarLai, C.-S., Lu, T.-F., Yang, C.-M., Lin, Y.-C., Pijanowska, D.G., Jaroszewicz, B., Body effect minimization using single layer structure for pH-ISFET applications (2010) Sensors and Actuators B Chem., 143 (2), pp. 494-499. , JanHenson, W.K., Ahmed, K.Z., Vogel, E.M., Hauser, J.R., Wortman, J.J., Venables, R.D., Xu, M., Venables, D., Estimating oxide thickness of tunnel oxides down to 1.4 nm using conventional capacitance-voltage measurements on MOS capacitors (1999) IEEE Electron Device Lett., 20 (4), pp. 179-181. , AprHauser, J.R., Ahmed, K., Characterization of ultra-thin oxides using electrical C-V and I-V measurements (1998) 1998 Int. Conf. Charact. Metrol. ULSI Technol., 235 (1998), pp. 235-239Chou, J.-C., Liao, L.P., Study on pH at the point of zero charge of TiO2 pH ion-sensitive field effect transistor made by the sputtering method (2005) Thin Solid Films, 476 (1), pp. 157-161. , AprKadoshima, M., Hiratani, M., Shimamoto, Y., Torii, K., Miki, H., Rutile-type TiO2 thin film for high-k gate insulator (2003) Thin Solid Films, 424, pp. 224-228Frank, M.M., Kim, S., Brown, S.L., Bruley, J., Copel, M., Hopstaken, M., Chudzik, M., Narayanan, V., Scaling the MOSFET gate dielectric: From high-k to higher-k? (2009) Microelectron. Eng., 86 (7-9), pp. 1603-1608. , JulKim, S., Brown, S.L., Rossnagel, S.M., Bruley, J., Copel, M., Hopstaken, M.J.P., Narayanan, V., Frank, M.M., Oxygen migration in TiO2 based higher-k gate stacks (2010) J Appl. Phys., 107 (5), p. 05410

Unravelling the Mechanistic Pathway of the Hydrogen Evolution Reaction Driven by a Cobalt Catalyst

Acord transformatiu CRUE-CSICA cobalt complex bearing a κ-NP ligand is presented (1 or Co(L), where L is (1E,1'E)-1,1'-(pyridine-2,6-diyl)bis(N-(3-(diphenylphosphanyl)propyl)ethan-1-imine). Complex 1 is stable under air at oxidation state Co thanks to the π-acceptor character of the phosphine groups. Electrochemical behavior of 1 reveals a two-electron Co/Co oxidation process and an additional one-electron reduction, which leads to an enhancement in the current due to hydrogen evolution reaction (HER) at E=−1.6 V vs Fc/Fc. In the presence of 1 equiv of bis(trifluoromethane)sulfonimide, 1 forms the cobalt hydride derivative Co(L)-H (2), which has been fully characterized. Further addition of 1 equiv of CoCp* (Cp* is pentamethylcyclopentadienyl) affords the reduced Co(L)-H (2) species, which rapidly forms hydrogen and regenerates the initial Co(L) (1). The spectroscopic characterization of catalytic intermediates together with DFT calculations support an unusual bimolecular homolytic mechanism in the catalytic HER with 1

CVD diamond coated silicon nitride self-mated systems : tribological behaviour under high loads

Friction and wear behaviour of self-mated chemical vapour deposited (CVD) diamond films coating silicon nitride ceramics (Si3N4) were investigated in ambient atmosphere. The tribological tests were conducted in a reciprocal motion ball-on-flat type tribometer under applied normal loads up to 80 N (~10 GPa). Several characterisation techniques - including scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman studies - were used in order to assess the quality, stress state and wear resistance of the coatings. In addition, a novel method is presented to estimate the wear coefficient of the diamond coated flat specimens from AFM and optical microscopy (OM) observations of the wear tracks

New Physics and CP Violation in Hyperon Nonleptonic Decays

The sum of the CP-violating asymmetries A(Lambda_-^0) and A(Xi_-^-) in hyperon nonleptonic decays is presently being measured by the E871 experiment. We evaluate contributions to the asymmetries induced by chromomagnetic-penguin operators, whose coefficients can be enhanced in certain models of new physics. Incorporating recent information on the strong phases in Xi->Lambda pi decay, we show that new-physics contributions to the two asymmetries can be comparable. We explore how the upcoming results of E871 may constrain the coefficients of the operators. We find that its preliminary measurement is already better than the epsilon parameter of K-Kbar mixing in bounding the parity-conserving contributions.Comment: 12 pages, 2 figure

Indicadores de qualidade do solo em sistemas de cultivo orgânico e convencional no semi-árido Cearense.

A qualidade do solo pode mudar com o passar do tempo, em decorrência de eventos naturais ou ações antrópicas. A adoção de práticas de cultivo orgânico reduz o revolvimento do solo, favorecendo a recuperação de suas propriedades físicas e químicas. Este trabalho teve como objetivo comparar propriedades físicas,químicas e biológicas de solos cultivados com algodão em bases orgânicas e no sistema convencional, assim como identificar as que possam ser utilizadas como indicadores de qualidade do solo. Selecionaram-se seis áreas submetidas ao cultivo orgânico e três ao cultivo convencional para coleta de amostras de solo deformadas e indeformadas, nas camadas de 0–10, 10–20 e 20–30 cm. Técnicas de estatística univariada e multivariada foram utilizadas para análise dos dados. Os resultados mostraram que os indicadores físicos e químicos testados individualmente não foram sensíveis para diferenciar as áreas sob sistema de cultivo orgânico daquelas sob cultivo convencional. No entanto, a aplicação de técnicas de análise multivariada – no caso, componentes principais e a discriminante de Anderson – permitiu a distinção entre algumas áreas cultivadas sob cultivo orgânico comparativamente às convencionais, até mesmo as que estavam em transição.Dos indicadores biológicos, a fauna edáfica mostrou-se mais precisa na avaliação da qualidade do solo, distinguindo de forma satisfatória as áreas sob sistema de cultivo orgânico das que estavam sob sistema convencional

Measurement of 73 Ge(n,γ) cross sections and implications for stellar nucleosynthesis

© 2019 The Author(s). Published by Elsevier B.V.73 Ge(n,γ) cross sections were measured at the neutron time-of-flight facility n_TOF at CERN up to neutron energies of 300 keV, providing for the first time experimental data above 8 keV. Results indicate that the stellar cross section at kT=30 keV is 1.5 to 1.7 times higher than most theoretical predictions. The new cross sections result in a substantial decrease of 73 Ge produced in stars, which would explain the low isotopic abundance of 73 Ge in the solar system.Peer reviewe

Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

The elliptic, $v_2$, triangular, $v_3$, and quadrangular, $v_4$, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range $|\eta|<0.8$ at different collision centralities and as a function of transverse momentum, $p_{\rm T}$, out to $p_{\rm T}=20$ GeV/$c$. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for $p_{\rm T}>8$ GeV/$c$. The small $p_{\rm T}$ dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to $p_{\rm T}=8$ GeV/$c$. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least $p_{\rm T}=8$ GeV/$c$ indicating that the particle type dependence persists out to high $p_{\rm T}$.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

The inclusive transverse momentum ($p_{\rm T}$) distributions of primary charged particles are measured in the pseudo-rapidity range $|\eta|<0.8$ as a function of event centrality in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV with ALICE at the LHC. The data are presented in the $p_{\rm T}$ range $0.15<p_{\rm T}<50$ GeV/$c$ for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor $R_{\rm{AA}}$ using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-$p_{\rm T}$ particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with $R_{\rm{AA}}\approx0.13$ at $p_{\rm T}=6$-7 GeV/$c$. Above $p_{\rm T}=7$ GeV/$c$, there is a significant rise in the nuclear modification factor, which reaches $R_{\rm{AA}} \approx0.4$ for $p_{\rm T}>30$ GeV/$c$. In peripheral collisions (70-80%), the suppression is weaker with $R_{\rm{AA}} \approx 0.7$ almost independently of $p_{\rm T}$. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284