1,720,996 research outputs found
A light-controlled resistive switching memory
Full text linkSketch of the configuration of a light-controlled resistive switching memory. Light enters through the Al 2O 3 uncovered surface and reaches the optically active p-Si substrate, where carriers are photogenerated and subsequently injected in the Al 2O 3 layer when a suitable voltage pulse is applied. The resistance of the Al 2O 3 can be switched between different non-volatile states, depending on the applied voltage pulse and on the illumination conditions.Fil: Ungureanu, Mariana. CIC nanoGUNE Consolider; EspañaFil: Zazpe, Raul. CIC nanoGUNE Consolider; EspañaFil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; Argentina. CIC nanoGUNE Consolider; EspañaFil: Stoliar, Pablo Alberto. Comisión Nacional de Energía Atómica; Argentina. CIC nanoGUNE Consolider; EspañaFil: Llopis, Roger. CIC nanoGUNE Consolider; EspañaFil: Casanova, Felix. CIC nanoGUNE Consolider; España. Basque Foundation for Science; EspañaFil: Hueso, Luis E.. CIC nanoGUNE Consolider; España. Basque Foundation for Science; Españ
Non-conventional metallic electrodes for organic field-effect transistors
Full text linkWe study micrometer-sized organic field-effect transistors with either Pd or NiFe metallic electrodes. Neither of these materials is commonly used in organic electronics applications, but they could prove to be particularly advantageous in certain niche applications such as organic spintronics. Using organic semiconductors with different carrier transport characteristics as active layer, namely n-type C60 fullerene and p-type Pentacene, we prove that Pd (NiFe) is a very suitable electrode for p- (n-) type semiconductors. In particular, we characterized devices with channel lengths in the order of the micrometer, a distance which has allowed us to evaluate the electronic behavior in a regime where the interfacial problems become predominant and it is possible to reach elevated longitudinal electric fields. Our experimental results agree well with a simple model based on rigid energy levels.Fil: Golmar, Federico. Instituto Nacional de Tecnología Industrial; Argentina. The CIC nanoGUNE Consolider; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gobbi, M.. The CIC nanoGUNE Consolider; EspañaFil: Llopis, Roger. The CIC nanoGUNE Consolider; EspañaFil: Stoliar, Pablo Alberto. The CIC nanoGUNE Consolider; España. Centre National de la Recherche Scientifique; Francia. Universidad Nacional de San Martín; ArgentinaFil: Casanova, Félix. Ikerbasque, Basque Foundation For Science; España. The CIC nanoGUNE Consolider; EspañaFil: Hueso, Luis E.. Ikerbasque, Basque Foundation For Science; España. The CIC nanoGUNE Consolider; Españ
Tuning the resistive switching properties of TiO2-x films
Full text linkWe study the electrical characteristics of TiO2-x-based resistive switching devices fabricated with different oxygen/argon flow ratio during the oxide thin film sputtering deposition. Upon minute changes in this fabrication parameter, three qualitatively different device characteristics were accessed in the same system, namely, standard bipolar resistive switching, electroforming-free devices, and devices with multi-step breakdown. We propose that small variations in the oxygen/ argon flow ratio result in relevant changes of the oxygen vacancy concentration, which is the key parameter determining the resistive switching behavior. The coexistence of percolative or non-percolative conductive filaments is also discussed. Finally, the hypothesis is verified by means of the temperature dependence of the devices in low resistance state.Fil: Ghenzi, Néstor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. CIC nanoGUNE; EspañaFil: Rozenberg, M.J.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. Université Paris Sud; FranciaFil: Llopis, R.. CIC nanoGUNE; EspañaFil: Levy, Pablo Eduardo. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hueso, Luis E.. Universidad del País Vasco; España. Fundación Vasca para la Ciencia; EspañaFil: Stoliar, Pablo Alberto. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. CIC nanoGUNE; Españ
Thermal effects on the switching kinetics of silver/manganite memristive systems
Full text linkWe investigate the switching kinetics of oxygen vacancy (Ov) diffusion in La(5/8-y)Pr(y)Ca(3/8)MnO(3)-Ag (LPCMO-Ag) memristive interfaces by performing experiments on the temperature dependence of the high resistance state under thermal cycling. Experimental results are well reproduced by numerical simulations based on thermally activated Ov diffusion processes and fundamental assumptions relying on a recent model proposed to explain bipolar resistive switching in manganite-based cells. The confident values obtained for activation energies and the diffusion coefficient associated to Ov dynamics constitute a validation test for both model predictions and Ov diffusion mechanisms in memristive interfaces.Fil: Stoliar, Pablo Alberto. Cic Nanogune; España. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Sánchez, M. J.. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Patterson, Germán Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Building memristive and radiation hardness TiO2-based junctions
Full text linkWe study micro-scale TiO2 junctions that are suitable to be used as resistive random-access memory nonvolatile devices with radiation hardness memristive properties. The fabrication and structural and electrical characterization of the junctions are presented. We obtained a retentivity of 105 s, an endurance of 104 cycles and reliable switching with short electrical pulses (time-width below 10 ns). Additionally, the devices were exposed to 25 MeV oxygen ions. Then, we performed electrical measurements comparing pristine and irradiated devices in order to check the feasibility of using these junctions as memory elements with memristive and radiation hardness properties.Fil: Ghenzi, Néstor. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rubi, Diego. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mangano, E.. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaFil: Gimenez, G.. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaFil: Lell, Julián Alejandro. Comisión Nacional de Energía Atómica; ArgentinaFil: Zelcer, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; ArgentinaFil: Stoliar, Pablo Alberto. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Universite de Nantes; Francia. Centre National de la Recherche Scientifique; FranciaFil: Levy, Pablo Eduardo. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Gerencia Química. CAC; Argentin
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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