1,721,338 research outputs found
ALD of SrTiO3 and Pt for Pt/SrTiO3/Pt MIM structures : growth and crystallization study
No full textMetal-insulator-metal (MIM) structures with ultrahigh-k strontium titanate films (SrTiO3, STO) and Pt as the dielectric and electrode material, respectively, have been prepared by ALD. The MIM structures were prepared with near-stoichiometric and Sr-rich ([Sr]/([Sr]+[Ti]) = 0.54 and 0.63, respectively) with a thickness of 15 nm. The influence of the rapid thermal annealing step at 600 °C in flowing N2, required to crystallize the STO, on the crystalline microstructure of the Pt bottom electrode and of the STO films has been investigated. Transmission electron microscopy and electron diffraction analysis evidenced that the morphology of the Pt bottom electrode is influenced by thermal treatment. Locally, an epitaxial relation between the textured Pt and the STO film could be found. However, X-ray and electron diffraction analysis showed that the STO crystalline grains were mainly randomly oriented. Top view TEM analysis revealed that the near-stoichiometric STO thin films deposited on Pt have a crystallization behavior comparable to those deposited on Al2O3, with nano-crack formation at the grain boundaries and an average grain size of ~ 100 nm
Room temperature sensing of O2 and CO by atomic layer deposition prepared ZnO films coated with Pt nanoparticles
No full textUltralow-power gas sensing devices need to operate without an energy consuming heater element. This requires the design of sensing devices that are so efficient that they can operate at room temperature (RT). Here, we report on the RT sensing performance of atomic layer deposition (ALD) prepared i-ZnO and Al-doped ZnO sensing devices. The sensitivity of these devices has been catalytically enhanced with ALD Pt nanoparticles (NPs). It was shown that the size distribution of the Pt NPs can be controlled by the number of Pt-ALD cycles. The Pt-enhanced sensing devices showed a reversible, proportional change in current response at RT upon exposure to O2 and CO. O2 could be detected, diluted in N2, down to 0.5%. CO could be detected, diluted in N2 in the presence of O2 and H2O, down to 20 ppm. Reference devices without Pt NPs showed no response, indicating the importance of the Pt NPs for the sensing mechanism. cop. The Electrochemical Society
Role of self- and boron-interstitial clusters in transient enhanced diffusion in silicon
No full textWe investigate the nucleation and evolution of boron-interstitial clusters (BIC), driven by high interstitial supersaturations, S(t), during Si implant damage annealing. The BICs are "fabricated" in a narrow band by overlapping the Si implant damage tail with a lightly doped B buried layer. The BIC band is found to be a net sink for interstitials at supersaturations S(t)>104. Our results suggest that silicon self-interstitial defects are the primary source of interstitials driving transient enhanced diffusion, and that BICs act as a secondary "buffer" for the interstitial supersaturatio
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
Plasma-Assisted Atomic Layer Deposition of SrTiO<sub>3</sub>: Stoichiometry and Crystallinity Study by Spectroscopic Ellipsometry
No full textStrontium titanate (SrTiO3, STO) films were deposited by plasma-assisted ALD using cyclopentadienyl-based Sr and Ti precursors with O2 plasma as the oxidizing agent. As determined from Rutherford backscattering spectroscopy (RBS), [Sr]/[Ti] ratios ranging from 0.73 to 2.13 were achieved for 30-40 nm thick films by tuning the [SrO]/[TiO2] ALD cycle ratio. Films deposited at 250 °C were amorphous and required post-deposition annealing to crystallize into the ultrahigh-k perovskite structure. The crystallization temperature strongly depended on the film composition as observed by X-ray diffraction (XRD) measurements after rapid thermal annealing (RTA). Using RBS and XRD data as a combined-cross reference, it was shown that the film stoichiometry and the crystallinity can be probed directly by spectroscopic ellipsometry (SE).</jats:p
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
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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