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Search for "surface defects" in Full Text gives 97 result(s) in Beilstein Journal of Nanotechnology.

AgCl-doped CdSe quantum dots with near-IR photoluminescence

  • Pavel A. Kotin,
  • Sergey S. Bubenov,
  • Natalia E. Mordvinova and
  • Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

Graphical Abstract
  • particularly relevant [12]. The most common way to obtain IR-PL in CdSe QDs is to add some optically active defects that reduce the energy of electron–hole recombination by trapping [13][14]. Charge carriers could be trapped by both surface defects [15][16] and volume defects [17][18][19][20][21]. It is known
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Published 29 May 2017

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

  • Hanaul Noh,
  • Alfredo J. Diaz and
  • Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

Graphical Abstract
  • force microscopy; multifrequency AFM; organic photovoltaics; polymer solar cells; surface defects; Introduction Polymer solar cells (PSCs) [1] have been widely studied due to the abundance of their constituents, their mechanical flexibility and light weight, as well as the possibility of low-cost roll
  • blend–electrode interface. In addition, we use bimodal AFM, a multifrequency AFM technique [18], to modify and remove the surface molecular layers. The series of AFM analyses and modification performed can be useful to better understand the nature of PSC surface defects. A detailed description of the
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Published 08 Mar 2017

Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

  • Ruchi Deshmukh,
  • Anurag Mehra and
  • Rochish Thaokar

Beilstein J. Nanotechnol. 2017, 8, 494–505, doi:10.3762/bjnano.8.53

Graphical Abstract
  • temperature by 120 °C and 150 °C respectively, thereby increasing the decomposition heat. The greater catalytic effect of snowflake particles, despite the smaller BET surface area, is attributed to the surface defects developed during their liquid-phase reduction. Recent studies also emphasize that the
  • or by thermal decomposition [18]. An alternative way to obtain complex hierarchical nanostructures is the controlled assembly of primary building blocks using electric and magnetic forces, capillary effects, and surface defects. Fascinating shapes such as, rice grain-like structures were formed by
  • –50 nm that show no surface defects or faults (Figure S2, Supporting Information File 1). A mixed population of twinned and un-twinned spherical nanoparticles with an average particle of ca. 15 nm is obtained (Figure 3a) when these seeds are ultrasonicated followed by the instantaneous addition of
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Published 23 Feb 2017

The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

  • Florent Pessina and
  • Denis Spitzer

Beilstein J. Nanotechnol. 2017, 8, 452–466, doi:10.3762/bjnano.8.49

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  • due to surface defects also sensitizes the energetic materials. Kumar et al. [16] succeeded in producing finer RDX particles by quickly injecting a very small volume (100 μL) of RDX dissolved in acetone into ultrapure water. The smallest mean particle size was 38 nm as determined by scanning electron
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Published 17 Feb 2017

Study of the surface properties of ZnO nanocolumns used for thin-film solar cells

  • Neda Neykova,
  • Jiri Stuchlik,
  • Karel Hruska,
  • Ales Poruba,
  • Zdenek Remes and
  • Ognen Pop-Georgievski

Beilstein J. Nanotechnol. 2017, 8, 446–451, doi:10.3762/bjnano.8.48

Graphical Abstract
  • structures increased to 2.3 and 2.0 eV, respectively. The observed changes in the high-resolution Zn 2p spectra indicate the enhanced presence of surface defects, i.e., the existence of Zn atoms in different chemical surroundings. Concomitantly, the plasma treatment introduces changes in the high-resolution
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Published 16 Feb 2017

Performance of colloidal CdS sensitized solar cells with ZnO nanorods/nanoparticles

  • Anurag Roy,
  • Partha Pratim Das,
  • Mukta Tathavadekar,
  • Sumita Das and
  • Parukuttyamma Sujatha Devi

Beilstein J. Nanotechnol. 2017, 8, 210–221, doi:10.3762/bjnano.8.23

Graphical Abstract
  • -P exhibits a weak, wide, visible emission from 500–700 nm upon excitation at 345 nm at room temperature as shown in Supporting Information File 1, Figure S4. The visible emission of ZnO basically arises from various surface defects, which can act as photogenerated electron trap states causing a loss
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Published 23 Jan 2017

Ordering of Zn-centered porphyrin and phthalocyanine on TiO2(011): STM studies

  • Piotr Olszowski,
  • Lukasz Zajac,
  • Szymon Godlewski,
  • Bartosz Such,
  • Rémy Pawlak,
  • Antoine Hinaut,
  • Res Jöhr,
  • Thilo Glatzel,
  • Ernst Meyer and
  • Marek Szymonski

Beilstein J. Nanotechnol. 2017, 8, 99–107, doi:10.3762/bjnano.8.11

Graphical Abstract
  • groups [13]. Those common surface defects are known to have an important effect on the molecule migration and surface diffusion barriers for Pd atoms [14][15], and as demonstrated by Kolmer et al., on the TiO2(011)-(2×1) surface, they play a very significant role in on-surface synthesis of polymers [16
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Published 11 Jan 2017

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

  • Anna Kosinova,
  • Ruth Schwaiger,
  • Leonid Klinger and
  • Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

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  • three in-plane orientations. The morphological stability and initial stages of dewetting of quasi-single-crystalline Au(Fe) thin films has been described in detail in [16]. Thus, this system represents a convenient model object for the studies of the effect of indentation-induced surface defects on the
  • Au(Fe) thin films. The goals of the present work were to determine the thermal stability of Au(Fe) films containing indentation-induced surface defects, and to establish the mechanisms of indent recovery. The latter goal should be considered in a wider framework of thermo-mechanical processing of
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Published 28 Dec 2016

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

  • Christoph Schreyvogel,
  • Vladimir Polyakov,
  • Sina Burk,
  • Helmut Fedder,
  • Andrej Denisenko,
  • Felipe Fávaro de Oliveira,
  • Ralf Wunderlich,
  • Jan Meijer,
  • Verena Zuerbig,
  • Jörg Wrachtrup and
  • Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

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  • conditions. For many quantum applications, near-surface NV− centres are required in order to efficiently couple out the emitted photoluminescence or to increase its sensitivity to external magnetic fields. However, one drawback is that near-surface NV centres are strongly affected by surface defects, surface
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Published 16 Nov 2016

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

  • Jakub S. Prauzner-Bechcicki,
  • Lukasz Zajac,
  • Piotr Olszowski,
  • Res Jöhr,
  • Antoine Hinaut,
  • Thilo Glatzel,
  • Bartosz Such,
  • Ernst Meyer and
  • Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

Graphical Abstract
  • the defect-free areas and lay flat at the defect sites. For regions free of defects on the (210) surface, molecules are preferentially adsorbed at the step edges. In defect areas, the surface defects compete with the step edges to adsorb molecules. It seems that in each of these adsorption geometries
  • densities has been investigated [33][43]. At a submonolayer coverage, molecules are predominantly found at the step edges and occasionally at the surface defects [33]. Only the molecules adsorbed on step edges running along surface rows have tilted geometries; the other molecules adopt a flat-lying
  • group is introduced instead of one phenyl group. At a low coverage, the COOH-ZnTPPs are also adsorbed in a flat-lying geometry and exhibit pronounced mobility. However, a considerable number of molecules are found immobilized at surface defects or domain boundaries, and these molecules can hardly be
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Published 09 Nov 2016

Dealloying of gold–copper alloy nanowires: From hillocks to ring-shaped nanopores

  • Adrien Chauvin,
  • Cyril Delacôte,
  • Mohammed Boujtita,
  • Benoit Angleraud,
  • Junjun Ding,
  • Chang-Hwan Choi,
  • Pierre-Yves Tessier and
  • Abdel-Aziz El Mel

Beilstein J. Nanotechnol. 2016, 7, 1361–1367, doi:10.3762/bjnano.7.127

Graphical Abstract
  • nodular growth triggered by the presence of surface defects created intentionally on the substrate as well as the high tilt angle between the magnetron source axis and the normal to the substrate, metal nanowires containing hillocks emerging out of the surface can be created. The approach is demonstrated
  • , the surface topography (roughness, defects, impurities) has a direct impact on the final structure and morphology of the material. As a consequence of the presence of substrate surface defects, the films deposited by a PVD process may contain undesired defects such as hillocks, pinholes, and craters
  • substrates with surface defects to grow metal nanowires with complex surface topography, which afterwards can be engineered on the nanoscale. We investigated the influence of the defects size and density on the final morphology of the nanowires. We demonstrated that the deposition time can impact the size of
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Published 29 Sep 2016

Reasons and remedies for the agglomeration of multilayered graphene and carbon nanotubes in polymers

  • Rasheed Atif and
  • Fawad Inam

Beilstein J. Nanotechnol. 2016, 7, 1174–1196, doi:10.3762/bjnano.7.109

Graphical Abstract
  • shortening of CNTs and in the introduction of surface defects at sidewalls [53]. It has been reported that sonication parameters such as time and aggressiveness, if not optimized, may damage the CNTs converting them into amorphous carbon nano-fibers [40]. Calendering: The calender is a three-roll mill that
  • coupled with ball milling [12][62][63]. Both sonication and ball milling reduce the sheet size and produce surface defects [64][65][66][67][68][69][70][71][72][73][74][75][76][77][78], and we believe that this impedes the improvement of K1C. Although calendering is an efficient way to disperse the
  • causing a shortening and producing surface defects which deleteriously affect the electrical properties and ordering of SWNTs in films and fibers [36][57]. Also, chemical functionalization can reduce the maximum nanotube buckling force by up to about 15% thereby deteriorating the mechanical properties of
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Published 12 Aug 2016

Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites

  • Protima Rauwel,
  • Augustinas Galeckas,
  • Martin Salumaa,
  • Frédérique Ducroquet and
  • Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

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  • 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The
  • means of optical absorption and photoluminescence spectroscopy [25]. We have already reported elsewhere that the free-standing cubic HfO2 nanoparticles are luminescent on their own with characteristic emission in the blue-green region of the visible spectra. This may be attributed to surface defects
  • , albeit with a notable discrepancy in the relative strength of the 3.1 eV emission component. In the case of free-standing cubic HfO2 nanoparticles, the nature of strong visible emission combines surface defects that act as charge trapping centers and oxygen vacancies due to the large presence of Hf3+ in
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Published 26 Jul 2016

Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

  • Jacek Wojnarowicz,
  • Roman Mukhovskyi,
  • Elzbieta Pietrzykowska,
  • Sylwia Kusnieruk,
  • Jan Mizeracki and
  • Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 721–732, doi:10.3762/bjnano.7.64

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  • ZnO NPs without doping amounted to 5.09 g/cm3. The difference between the nano density and the theoretical density of ZnO can result above all from surface defects, the presence of Zn(OH)2 hydroxides and the non-stoichiometric composition. The density of Zn1−xMnxO, irrespectively of the content of Mn2
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Published 19 May 2016

Orientation of FePt nanoparticles on top of a-SiO2/Si(001), MgO(001) and sapphire(0001): effect of thermal treatments and influence of substrate and particle size

  • Martin Schilling,
  • Paul Ziemann,
  • Zaoli Zhang,
  • Johannes Biskupek,
  • Ute Kaiser and
  • Ulf Wiedwald

Beilstein J. Nanotechnol. 2016, 7, 591–604, doi:10.3762/bjnano.7.52

Graphical Abstract
  • FePt particles on MgO(001). The enhanced sharpness of the rings can be attributed to an improved crystallinity of the nanoparticles after annealing at 650 °C, but also to decreasing charging effects due to the formation of surface defects in the MgO substrate leading to better electrical conductivity
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Published 21 Apr 2016

Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

  • Yongfeng Tong,
  • Tingming Jiang,
  • Azzedine Bendounan,
  • Makri Nimbegondi Kotresh Harish,
  • Angelo Giglia,
  • Stefan Kubsky,
  • Fausto Sirotti,
  • Luca Pasquali,
  • Srinivasan Sampath and
  • Vladimir A. Esaulov

Beilstein J. Nanotechnol. 2016, 7, 263–277, doi:10.3762/bjnano.7.24

Graphical Abstract
  • [105][106][107][108][109][110]. This has been related to low coordination sites [109][110] and to the density of steps and different kinds of surface defects. Variability, to the extent of dissociation processes, could thus be expected depending upon the structure of the surface. Selenophene on Cu(111
  • the preparation procedures appear to be reasonably good. We would relate this at least partly to surface morphology, since reactivity can be large at low coordination sites and depends on the density of steps and different kinds of surface defects. It is important to delineate this from the point of
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Published 17 Feb 2016

Characterisation of thin films of graphene–surfactant composites produced through a novel semi-automated method

  • Nik J. Walch,
  • Alexei Nabok,
  • Frank Davis and
  • Séamus P. J. Higson

Beilstein J. Nanotechnol. 2016, 7, 209–219, doi:10.3762/bjnano.7.19

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  • reduced number of layers. The D and D’ bands are caused by disorder in the graphene flakes. The D’ band is present when there are surface defects, such as charging or other impurities adsorbed onto the surface. The D band is caused by edge defects such as a “zig-zag” or “chair” shape on the edge. Edge
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Published 08 Feb 2016

Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

  • Kuang-Yang Kou,
  • Yu-En Huang,
  • Chien-Hsun Chen and
  • Shih-Wei Feng

Beilstein J. Nanotechnol. 2016, 7, 75–80, doi:10.3762/bjnano.7.9

Graphical Abstract
  • ]. The variation in the physical properties of nanostructures drastically influences the optoelectronic properties of ZnO [11][12][13]. X-ray-excited optical luminescence of ZnO nanoneedles shows a sharp band gap emission and a broad red emission related to surface defects, while that of ZnO
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Published 20 Jan 2016

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

  • Urs Gysin,
  • Thilo Glatzel,
  • Thomas Schmölzer,
  • Adolf Schöner,
  • Sergey Reshanov,
  • Holger Bartolf and
  • Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

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  • harmonic contributions between the individual PSD signals, influence the measurements [22]. Furthermore, band-bending effects due to surface defects and the applied ac voltage may change the measured VCPD [38][39]. Hence KPFM is an ideal experimental technique to visualize electronic properties of all kind
  • samples of interest are semiconductor surfaces involving various doping concentrations and even cross-sections of interfaces [41][42]. Such measurements are influenced by surface band-bending effects induced by either intrinsic surface defects, adsorbates, interface states and last but not least by the
  • doping concentration. Since KPFM is a non destructive, surface sensitive technique, e.g., compared to SSRM, information on bulk properties have to be extracted from the surface sensitive information. Several approaches have been applied in recent years for this purpose, e.g., avoiding surface defects by
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Published 28 Dec 2015

Mapping bound plasmon propagation on a nanoscale stripe waveguide using quantum dots: influence of spacer layer thickness

  • Chamanei S. Perera,
  • Alison M. Funston,
  • Han-Hao Cheng and
  • Kristy C. Vernon

Beilstein J. Nanotechnol. 2015, 6, 2046–2051, doi:10.3762/bjnano.6.208

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  • vicinity of the waveguide can be excited via propagating plasmons resulting in PL around the waveguide. We interpret the brighter QD PL along the waveguide edges is arising due to scattering of the propagating plasmons due to surface defects present along the edges. Intensity of the QD PL should be
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Published 19 Oct 2015

Transformations of PTCDA structures on rutile TiO2 induced by thermal annealing and intermolecular forces

  • Szymon Godlewski,
  • Jakub S. Prauzner-Bechcicki,
  • Thilo Glatzel,
  • Ernst Meyer and
  • Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

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  • PTCDA molecules indicates high mobility at room temperature that enables diffusion towards terrace edges. There is, however, a substantial number of molecules trapped at terraces. They do not form any ordered structures and are likely pinned by surface defects. The latter observation is further
  • the [001] crystallographic direction. This indicates that in adopting the most favoured geometry upon adsorption, the key role is played by the molecule–substrate interactions. For on-terrace species, immobilization is reached by additional interactions with surface defects. For low, sub-monolayer
  • demonstrated that the molecular structures could be changed by thermal annealing of the system and also by the amount of molecules. At low coverage, the molecules adsorb mainly as single entities at surface steps and surface defects at terraces. At moderate coverage, the molecules deposited at room temperature
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Published 10 Jul 2015

Addition of Zn during the phosphine-based synthesis of indium phospide quantum dots: doping and surface passivation

  • Natalia E. Mordvinova,
  • Alexander A. Vinokurov,
  • Oleg I. Lebedev,
  • Tatiana A. Kuznetsova and
  • Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2015, 6, 1237–1246, doi:10.3762/bjnano.6.127

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  • shows the normalized PL spectra of samples with different amounts of Zn. The spectrum of non-doped QDs exhibit a noticeable peak related to surface defects. Zn atoms have a great influence on the surface defects, i.e., already a small amount of Zn on the surface of the QDs results in fewer surface
  • dangling bonds, which reduces the defect peak and enhances the excitonic peak. However, the tail does not completely disappear and we suggest that it is not related to surface defects but to Zn-doping. Furthermore, we can clearly see that the form of the spectra hardly changes with increasing Mnom. The PL
  • spectra were deconvoluted in energy coordinates by using two Gaussian functions: One is related to the excitonic peak and the other to surface defects (Figure 9a) in case of non-doped sample and to the dopant in case of doped QDs, respectively (Figure 9b). Figure 10a shows how the excitonic peaks change
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Published 01 Jun 2015

Observing the morphology of single-layered embedded silicon nanocrystals by using temperature-stable TEM membranes

  • Sebastian Gutsch,
  • Daniel Hiller,
  • Jan Laube,
  • Margit Zacharias and
  • Christian Kübel

Beilstein J. Nanotechnol. 2015, 6, 964–970, doi:10.3762/bjnano.6.99

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  • (Figure 3a), the Ar-annealed sample exhibits a high density of surface defects. It appears that part of the layer has been removed (darker regions). These surface damages are absent for the N2-annealed sample, which is very homogeneous across the whole sample area. Similar effects have been reported for
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Published 15 Apr 2015

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

  • Hamdi Baccar,
  • Atef Thamri,
  • Pierrick Clément,
  • Eduard Llobet and
  • Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

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  • Pd nanoparticles. Sputtering allows for an oxygen plasma treatment that removes amorphous carbon from the surface of the carbon nanotubes and creates oxygenated surface defects in which metal nanoparticles nucleate within a few minutes. The decoration with the 2 nm Pt or the 3 nm Pd nanoparticles is
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Published 09 Apr 2015

Protein corona – from molecular adsorption to physiological complexity

  • Lennart Treuel,
  • Dominic Docter,
  • Michael Maskos and
  • Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

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  • broader view of the situation: While single atoms or atomic scale surface defects are of high importance for the adsorption of small molecules that are frequently considered in catalytic mechanisms, the size of the adsorbing protein, typically several nanometers, leads to an interaction process averaging
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Published 30 Mar 2015
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