Ultramicroscopy Journal Impact Factor & Information

Publisher: Microscopy Society of America; Israel Society for Microscopy; Scandinavian Society for Electron Microscopy; Netherlands Society of Electron Microscopy; Swiss Society for Electron Microscopy; All authors, Elsevier

Journal description

Scientists engaged in ultrastructure research seem to fall into two overlapping categories. One group uses existing tools and methods to advance knowledge in particular disciplines. The second group is committed to advancing the tools and methods themselves. For the benefit of both groups, this work finds its outlet in Ultramicroscopy, a journal initiated to provide a forum for investigators and to concentrate otherwise widely dispersed knowledge, promoting cross-fertilization between the two groups. This communication between developer and user covers all aspects - fundamental and technical - pertaining to ultramicroscopic elucidation of structure, ranging from particle optics to radiation interaction.

Current impact factor: 2.75

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 2.745
2012 Impact Factor 2.47
2011 Impact Factor 2.471
2010 Impact Factor 2.061
2009 Impact Factor 2.067
2008 Impact Factor 2.629
2007 Impact Factor 1.996
2006 Impact Factor 1.706
2005 Impact Factor 2.49
2004 Impact Factor 2.215
2003 Impact Factor 1.665
2002 Impact Factor 1.772
2001 Impact Factor 1.89
2000 Impact Factor 1.695
1999 Impact Factor 2.244
1998 Impact Factor 2.045
1997 Impact Factor 1.6

Impact factor over time

Impact factor
Year

Additional details

5-year impact 2.35
Cited half-life 7.80
Immediacy index 0.78
Eigenfactor 0.02
Article influence 1.01
Website Ultramicroscopy website
Other titles Ultramicroscopy (Online)
ISSN 0304-3991
OCLC 39196475
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Elsevier

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Pre-print allowed on any website or open access repository
    • Voluntary deposit by author of authors post-print allowed on authors' personal website, arXiv.org or institutions open scholarly website including Institutional Repository, without embargo, where there is not a policy or mandate
    • Deposit due to Funding Body, Institutional and Governmental policy or mandate only allowed where separate agreement between repository and the publisher exists.
    • Permitted deposit due to Funding Body, Institutional and Governmental policy or mandate, may be required to comply with embargo periods of 12 months to 48 months .
    • Set statement to accompany deposit
    • Published source must be acknowledged
    • Must link to journal home page or articles' DOI
    • Publisher's version/PDF cannot be used
    • Articles in some journals can be made Open Access on payment of additional charge
    • NIH Authors articles will be submitted to PubMed Central after 12 months
    • Publisher last contacted on 18/10/2013
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Artefacts in atom probe tomography can impact the compositional analysis of microstructure in atom probe studies. To determine the integrity of information obtained, it is essential to understand how the positioning of features influences compositional analysis. By investigating the influence of feature orientation within atom probe data on measured composition in microstructural features within an AA2198 Al alloy, this study shows differences in the composition of T1 (Al2CuLi) plates that indicates imperfections in atom probe reconstructions. The data fits a model of an exponentially-modified Gaussian that scales with the difference in evaporation field between solutes and matrix. This information provides a guide for obtaining the most accurate information possible. Copyright © 2015 Elsevier B.V. All rights reserved.
    Ultramicroscopy 04/2015; DOI:10.1016/j.ultramic.2015.04.005
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    ABSTRACT: We look at the new challenges associated with Atom Probe Tomography of insulators and semiconductors with regard to local fields inside and on the surface of such materials. The theoretical discovery that in high fields the band gap in these materials is drastically reduced to the point where at the evaporation field strength it vanishes will be crucial in our discussion. To understand Atom Probe results on the field evaporation of insulators and semiconductors we use density functional theory on ZnO clusters to follow the structural and electronic changes during field evaporation and to obtain potential energy curves, HOMO-LUMO gaps, field distributions, desorption pathways and fragments, dielectric constants, and polarizabilities. We also examine the effects of electric field reversal on the evaporation of ZnO and compare the results with Si. Copyright © 2015 Elsevier B.V. All rights reserved.
    Ultramicroscopy 03/2015; DOI:10.1016/j.ultramic.2015.03.011
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    ABSTRACT: An analytical model describing the field evaporation dynamics of a tip made of a thin layer deposited on a substrate is presented in this paper. The difference in evaporation field between the materials is taken into account in this approach in which the tip shape is modeled at a mesoscopic scale. It was found that the non-existence of sharp edge on the surface is a sufficient condition to derive the morphological evolution during successive evaporation of the layers. This modeling gives an instantaneous and smooth analytical representation of the surface that shows good agreement with finite difference simulations results, and a specific regime of evaporation was highlighted when the substrate is a low evaporation field phase. In addition, the model makes it possible to calculate theoretically the tip analyzed volume, potentially opening up new horizons for atom probe tomographic reconstruction. Copyright © 2015. Published by Elsevier B.V.
    Ultramicroscopy 03/2015; DOI:10.1016/j.ultramic.2015.03.010
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    ABSTRACT: Environmental transmission electron microscopy (TEM) has enabled in situ experiments in a gaseous environment with high resolution imaging and spectroscopy. Addressing scientific challenges in areas such as catalysis, corrosion, and geochemistry can require pressures much higher than the ∼20mbar achievable with a differentially pumped environmental TEM. Gas flow stages, in which the environment is contained between two semi-transparent thin membrane windows, have been demonstrated at pressures of several atmospheres. However, the relationship between the pressure at the sample and the pressure drop across the system is not clear for some geometries. We demonstrate a method for measuring the gas pressure at the sample by measuring the ratio of elastic to inelastic scattering and the defocus of the pair of thin windows. This method requires two energy filtered high-resolution TEM images that can be performed during an ongoing experiment, at the region of interest. The approach is demonstrated to measure greater than atmosphere pressures of N2 gas using a commercially available gas-flow stage. This technique provides a means to ensure reproducible sample pressures between different experiments, and even between very differently designed gas-flow stages. Copyright © 2015 Elsevier B.V. All rights reserved.
    Ultramicroscopy 02/2015; 153. DOI:10.1016/j.ultramic.2015.01.002
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    ABSTRACT: A newly developed carbon cone nanotip (CCnT) has been used as field emission cathode both in low voltage SEM (30 kV) electron source and high voltage TEM (200 kV) electron source. The results clearly show, for both technologies, an unprecedented stability of the emission and the probe current with almost no decay during 1 h, as well as a very small noise (rms less than 0.5%) compared to standard sources which use tungsten tips as emitting cathode. In addition, quantitative electric field mapping around the FE tip have been performed using in situ electron holography experiments during the emission of the new tip. These results show the advantage of the very high aspect ratio of the new CCnT which induces a strong enhancement of the electric field at the apex of the tip, leading to very small extraction voltage (some hundred of volts) for which the field emission will start. The combination of these experiments with emission current measurements has also allowed to extract an exit work function value of 4.8 eV.KeywordsField emissionElectrons sourcesElectron holographyCarbon tips
    Ultramicroscopy 12/2014; DOI:10.1016/j.ultramic.2014.11.021
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    ABSTRACT: We present the design and performance of a simple and compact magnetic force microscope (MFM), whose tip-sample coarse approach is implemented by the piezoelectric tube scanner (PTS) itself. In brief, a square rod shaft is axially spring-clamped on the inner wall of a metal tube which is glued inside the free end of the PTS. The shaft can thus be driven by the PTS to realize image scan and inertial stepping coarse approach. To enhance the inertial force, each of the four outer electrodes of the PTS is driven by an independent port of the controller. The MFM head is so compact that it can easily fit into the 52 mm low temperature bore of a 20 T superconducting magnet. The performance of the MFM is demonstrated by imaging a manganite thin film at low temperature and in magnetic fields up to 15 T.
    Ultramicroscopy 12/2014; 147. DOI:10.1016/j.ultramic.2014.07.011
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    ABSTRACT: Thermal magnetic field noise from magnetic and non-magnetic conductive parts close to the electron beam recently has been identified as a reason for decoherence in high-resolution transmission electron microscopy (TEM). Here, we report about new experimental results from measurements for a layered structure of magnetic and non-magnetic materials. For a simplified version of this setup and other situations we derive semi-analytical models in order to predict the strength, bandwidth and spatial correlation of the noise fields. The results of the simulations are finally compared to previous and new experimental data in a quantitative manner.
    Ultramicroscopy 11/2014; DOI:10.1016/j.ultramic.2014.11.022
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    ABSTRACT: We investigate the implications of the form of the spatial coherence function, also referred to as the effective source distribution, for quantitative analysis in scanning transmission electron microscopy, and in particular for interpreting the spatial origin of imaging and spectroscopy signals. These questions are explored using three different source distribution models applied to a GaAs crystal case study. The shape of the effective source distribution was found to have a strong influence not only on the scanning transmission electron microscopy (STEM) image contrast, but also on the distribution of the scattered electron wavefield and hence on the spatial origin of the detected electron intensities. The implications this has for measuring structure, composition and bonding at atomic resolution via annular dark field, X-ray and electron energy loss STEM imaging are discussed.
    Ultramicroscopy 11/2014; 146. DOI:10.1016/j.ultramic.2014.04.008
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    ABSTRACT: This paper reports the effect of dimensions of microcantilever (MC) on its resonance frequency and bending upon adsorption of water molecules. Study is conducted on three MCs having the dimensions of 450 x 40 x 2.5 μm3 (MC1), 225 x 30 x 3 μm3 (MC2) and 125 x 35 x 4.5 μm3 (MC3). The measured resonant frequency showed the expected negative shift in MC1, initially positive followed by a negative shift in MC2 and only positive shift in MC3 during adsorption. This behavior is attributed to changes in the stiffness of the MC associated with the surface stress. The surface stress generated on the MC has been derived from its bending measurements upon water adsorption. The change in the stiffness of MC evaluated from an independent estimate of expected frequency shift showed that the relative stiffness change of MC increases linearly with the surface stress scaled with cube of width to height ratio of MCs, confirming the dimensional dependence of adsorption induced stiffness change.
    Ultramicroscopy 11/2014; 146. DOI:10.1016/j.ultramic.2014.06.007
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    ABSTRACT: The reduced density matrix completely describes the quantum state of an electron scattered by an object in transmission electron microscopy. However, the detection process restricts access to the diagonal elements only. The off-diagonal elements, determining the coherence of the scattered electron, may be obtained from electron holography. In order to extract the influence of the object from the off-diagonals, however, a rigorous consideration of the electron microscope influences like aberrations of the objective lens and the Möllenstedt bisprism in presence of partial coherence is required. Here, we derive a holographic transfer theory based on the generalization of the transmission cross-coefficient including all known holographic phenomena. We furthermore apply a particular simplification of the theory to the experimental analysis of aloof beam electrons scattered by plane silicon surfaces.
    Ultramicroscopy 11/2014; 146. DOI:10.1016/j.ultramic.2014.07.007
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    ABSTRACT: The development of ultrafast electron microscopy (UEM) and variants thereof (e.g., photon-induced near-field electron microscopy, PINEM) has made it possible to image atomic-scale dynamics on the femtosecond timescale. Accessing the femtosecond regime with UEM currently relies on the generation of photoelectrons with an ultrafast laser pulse and operation in a stroboscopic pump-probe fashion. With this approach, temporal resolution is limited mainly by the durations of the pump laser pulse and probe electron packet. The ability to accurately determine the duration of the electron packets, and thus the instrument response function, is critically important for interpretation of dynamics occurring near the temporal resolution limit, in addition to quantifying the effects of the imaging mode. Here, we describe a technique for in situ characterization of ultrashort electron packets that makes use of coupling with photons in the evanescent near-field of the specimen. We show that within the weakly-interacting (i.e., low laser fluence) regime, the zero-loss peak temporal cross-section is precisely the convolution of electron packet and photon pulse profiles. Beyond this regime, we outline the effects of non-linear processes and show that temporal cross-sections of high-order peaks explicitly reveal the electron packet profile, while use of the zero-loss peak becomes increasingly unreliable.
    Ultramicroscopy 11/2014; DOI:10.1016/j.ultramic.2014.08.001
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    ABSTRACT: In the last years, a new AFM based dielectric spectroscopy approach has been developed for measuring the dielectric relaxation of materials at the nanoscale, the so called nanoDielectric Spectroscopy (nDS). In spite of the effort done so far, some experimental aspects of this technique remain still unclear. In particular, one of these aspects is the possibility of extending the experimental frequency range, to date limited at high frequencies by the resonance frequency of the AFM cantilever as a main factor. In order to overcome this limitation, the electrical excitation of cantilever higher eigenmodes for measuring the dielectric relaxation is here explored. Thus, in this work we present a detailed experimental analysis of the electrical excitation of the cantilever second eigenmode. Based on this analysis we show that the experimental frequency range of the AFM based dielectric spectroscopy can be extended by nearly two decades with a good signal-to-noise ratio. By using the combination of first and second cantilever eigenmodes we study dissipation processes on well known PVAc based polymeric samples. Both, relaxation spectra and images with molecular dynamics contrast were thus obtained over this broader frequency range.
    Ultramicroscopy 11/2014; 146. DOI:10.1016/j.ultramic.2014.06.006
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    ABSTRACT: In order to achieve the highest resolution in aberration-corrected (AC) high-resolution transmission electron microscopy (HRTEM) images, high electron doses are required in which only a few samples can withstand. In this paper we perform dose-dependent AC-HRTEM image calculations, and study the dependence of the signal-to-noise ratio, atom contrast and resolution on electron dose and sampling. We introduce dose-dependent contrast, which can be used to evaluate the visibility of objects under different dose conditions. Based on our calculations, we determine optimum samplings for high and low electron dose imaging conditions.
    Ultramicroscopy 10/2014; 145. DOI:10.1016/j.ultramic.2014.01.010