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Writing with atoms： Oxygen adatoms on the MoO2/Mo（110） surface

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Nano Research 2013年第12期6卷 929-937页

作者： Sergey A. Krasnikov.Olaf Lubben Barry E. Murphy Sergey I. Bozhko Alexander N. Chaika Natalia N. Sergeev. bren.an.bulfin.an. igor v. shvets Centre for Research on Adaptiv. Nanostructures and Nanodev.ces School of Physics Trinity College Dublin Dublin 2 Ireland Institute of Solid State Physics Russian Academy of Sciences Chernogolovka Moscow District 142432 Russia School of Chemistry University of Leeds Leeds LS2 9JT UK

Writing at the nanoscale using the desorption of oxygen adatoms from the oxygen-rich MoO2＋x/Mo（110） surface is demonstrated by scanning tunnelling microscopy （STM）. High-temperature oxidation of the Mo（110） surface results in a strained, bulk-like MOO2（010） ultra-thin film with an O-Mo-O trilayer structure. Due to the lattice mismatch between the Mo（110） and the MOO2（010）, the latter consists of well-ordered molybdenum oxide nanorows separated by 2.5 nm. The MoO2（010）/Mo（110） structure is confirmed by STM data and density functional theory calculations. Further oxidation results in the oxygen-rich MoOa^x/Mo（110） surface, which exhibits perfectly aligned double rows of oxygen adatoms, imaged by STM as bright protrusions. These adatoms can be remov.d from the surface by scanning （or pulsing） at positiv. sample biases greater than 1.5 v. Tip mov.ment along the surface can be used for controlled lithography （or writing） at the nanoscale, with a minimum feature size of just 3 nm. By mov.ng the STM tip in a predetermined fashion, information can be written and read by applying specific biases between the surface and the tip.

关键词： scanning tunnellingmicroscopy inelastic tunnelling atom manipulation molybdenum oxide

Fe Nanoclusters on the Ge（001） Surface Studied by Scanning Tunneling Microscopy, Density Functional Theory Calculations and X-Ray Magnetic Circular Dichroism

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Nano Research 2011年第10期4卷 971-978页

作者： Olaf LUbben Sergey A. Krasnikov.Alexei B. Preobrajenski Barry E. Murphy igor v. shvets Centre for Research on Adaptiv. Nanostructures and Nanodev.ces （CRANN） School of Physics Trinity College Dublin Dublin 2 Ireland MAX-lab Lund University Box 118. 22100 Lund Sweden

The growth of Fe nanoclusters oN the Ge（001） surface has been studied using low-temperature scanning tunneling microscopy （STM） and density functional theory （DFT） calculations. STM results indicate that Fe nucleates on the Ge（001） surface, forming well-ordered nanoclusters of uniform size. Depending on the preparation conditions, two types of nanoclusters were observ.d hav.ng either four or sixteen Fe atoms within a nanocluster. The results were confirmed by DFT calculations. Annealing the nanoclusters at 420 K leads to the formation of nanorow structures, due to cluster mobility at such temperature. The Fe nanoclusters and nanorow structures formed on the Ge（001） surface show a superparamagnetic behav.our as measured by X-ray magnetic circular dichroism.

关键词： Ge(001) iron nanoclusters self-assembly scanning tunnelling microscopy X-ray magnetic circular dichroism density functional theory calculations

Continuous wafer-scale graphene on cubic-SiC（O01）

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Nano Research 2013年第8期6卷 562-570页

作者： Alexander N. Chaika Olga v. Molodtsov. Alexei A. Zakharov.Dmitry Marchenko Jaime Sanchez-Barrig Andrei v.rykhalov.igor v. shvets v.ctor Yu. Aristov Institute of Solid State Physics RAS Chemogolovka Moscow District 142432 Russia Centre for Research on Adaptiv. Nanostructures and Nanodev.ces (CRANN) School of Physics Trinity College Dublin 2 Ireland HASYLAB at DESY D-22607 Hamburg Germany MAX-lab Lund University Box 118 22100 Lund Sweden Helmholtz-Zentrum Berlin für Materialien und Energie D- 12489 Berlin Germany

The atomic and electronic structure of graphene synthesized on commercially av.ilable cubic-SiC（001）/Si（001） wafers hav. been studied by low energy electron microscopy （LEEM）, scanning tunneling microscopy （STM）, low energy electron diffraction （LEED）, and angle resolv.d photoelectron spectroscopy （ARPES）. LEEM and STM data prov. the wafer-scale continuity and uniform thickness of the graphene ov.rlayer on SIC（001）. LEEM, STM and ARPES studies rev.al that the graphene ov.rlayer on SIC（001） consists of only a few monolayers with physical properties of quasi-freestanding graphene. Atomically resolv.d STM and micro-LEED data show that the top graphene layer consists of nanometer-sized domains with four different lattice orientations connected through the 〈110〉-directed boundaries. ARPES studies rev.al the typical electron spectrum of graphene with the Dirac points close to the Fermi lev.l. Thus, the use of technologically relev.nt SiC（001）/Si（001） wafers for graphene fabrication repre-sents a realistic way of bridging the gap between the outstanding properties of graphene and their applications.

关键词： graphene cubic-SiC(001) STM ARPES LEEM LEED

Heat Transfer and Fluid Flow ov.r a Single Disk in a Fluid Rotating as a Rigid Body

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Journal of Thermal Science 2004年第3期13卷 279-282页

作者： igor v. SHEv.HUK Matthias H. BUSCHMANN Institute of Engineering Thermophysics Ukrainian National Academy of Sciences 2a Zhelyabov St. Kiev 03057 UkraineInstitute of Fluid Mechanics Dresden University of Technology 01062 Dresden Germany

Laminar heat transfer problem is analyzed for a disk rotating with the angular speed ωin a co-rotating fluid (with the angular speed Ω). The fluid is swirled in accordance with a forced-v.rtex law, it rotates as a solid body at β= Ω/ω= const. Radial v.riation of the disk’s surface temperature follows a power law. An exact numerical solution of the problem is obtained basing on the self-similar profiles of the local temperature of fluid, its static pressure and v.locity components. Numerical computations were done at the Prandtl numbers Pr = 1(?)0.71. It is shown that with increasing βboth radial and tangential components of shear stresses decrease, and to zero v.lue at β= 1. Nusselt number is practically constant at β= 0(?) 0.3 (and ev.n has a point of a maximum in this region); Nu decrease noticeably for larger βv.lues.

关键词： rotating disk heat transfer fluid flow Nusselt number swirl.

Inv.stigation of coupled cobalt-silv.r nanoparticle system by plan v.ew TEM

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Progress in Natural Science:Materials International 2012年第3期22卷 186-192页

作者： Daniel Fox Ruggero v.rre brendan J. O'Dowd Sunil K. Arora Colm C. Faulkner igor v. shvets School of Physics and CRANN Trinity College Dublin CRANN Adv.nced Microscopy Laboratory Trinity College Dublin

We present a transmission electron microscopy (TEM) inv.stigation of a coupled cobalt and silv.r nanoparticle system. A plan v.ew in situ lift-out method for preparing samples for TEM using the focused ion beam (FIB) microscope was used. This technique is used to prepare high quality TEM samples with site specificity in a short time and with a high success rate. We demonstrate the ability of the plan v.ew sample preparation technique to prov.de information about an ordered system of nanoparticles which could not be observ.d using standard FIB cross sectioning of the sample. High resolution TEM and energy dispersiv. X-ray spectroscopy mapping of both cross sectional and plan v.ew samples are presented, clearly showing the significant benefit of plan v.ew TEM analysis for certain samples.

关键词： Focused ion beam Transmission electron microscopy Lift-out Co Ag Nanoparticle

Prov.nance of Precambrian Fe- and Al-rich Metapelites in the Yenisey Ridge and Kuznetsk Alatau, Siberia: Geochemical Signatures

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Acta Geologica Sinica(English Edition) 2007年第3期81卷 409-423页

作者： igor I. LIKHANOv.v.adimir v. REv.RDATTO Institute of Geology and Mineralogy Siberian Branch Russian Academy of SciencesPr. Acad. Koptyuga3Novosibirsk630090Russian Federation

Major, trace and rare earth element contents of Fe- and Al-rich metapelites from the Korda （Yenisey Ridge） and Amar （Kuznetsk Alatau） formations were determined to examine the nature, origin and ev.lution of their protoliths. Results indicate that these rocks are the redeposited and metamorphosed products of Precambrian kaolinitic weathering crusts, while the geochemical distinctions between the studied metapelites are determined by different weathering conditions in the source area and tectonic settings. The protolith of the Korda Formation metapelites was produced by erosion products of the post-Archean granitoid rocks, which accumulated under humid climate conditions in shallow-water basins along the continental margin. The geochemical characteristics of the deeper primary deposits of the Amar Formation suggest that v.lcanogenic material of mafic composition deriv.d from an island-arc env.ronment had a major role in supplying the erosion zone. These results agree with lithofacies data and with the geodynamic reconstruction of the ev.lution of the Yenisey Ridge and Kuznetsk Alatau during the Mesoproterozoic and Neoproterozoic, respectiv.ly. It was shown that REEs had limited mobility during contact metamorphism. The coherent mobility of REEs during collisional metamorphism may be attributed both to mineral reactions responsible for modal changes and to local chemical heterogeneity inherited from the initial protolith.

关键词： geochemistry protolith pelitic schists Kuznetsk Alatau Yenisey Ridge Russia

Microheterogeneity of the Koupol Deposit Fahlores as a Reflection of Changing of Physicochemical Parameters of the Ore-Forming Solution

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Journal of Earth Science 2013年第2期24卷 179-187页

作者： igor'v.Kemkin Raisa A Kemkina Far East Geological Institute Far Eastern Branch of the Russian Academy of Sciences Far East Federal Univ.rsity

New data on a zonal structure of the Koupol deposit fahlores grains are giv.n, and features of their chemism are shown. The fahlores chemical composition within the zones ev.lv.s from essentially arsenious （Fe-tennantite and Zn-tennantite）, through mixed fahlores （Zn-tennantitetetrahedrite arsenious and Zn-tennantite-tetrahedrite antimonous）, to essential antimonous （Ag-bearing Zn-tetrahedrite）. v.rying chemical composition manifested as mineralogical-geochemical zonation of the fahlores grains is caused by changes of physicochemical conditions of the ore forming process during the time.

关键词： fahlore mineralogical-geochemical zonation physicochemical condition Koupol deposit.

Understanding bottom-up continuous hydrothermal synthesis of nanoparticles using empirical measurement and computational simulation

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Nano Research 2016年第11期9卷 3377-3387页

作者： Jose Sierra-Pallarest Thomas Huddle Juan Garcia-Serna Esther Alonso Fidel Mato igor shvets Olaf Luebben Maria Jose Cocero Edward Lester Fluids Engineering Group Energy and Fluid Mechanics Engineering Department University of Valladolid Paseo del Cauce 59 47010 Valladolid Spain Adv.nced Materials Research Group the University of Nottingham University Park Nottingham NG7 2RD UK High Pressure Processes Group Department of Chemical Engineering and Environmental Technology University of Valladolid C/Prado de la Magdalena s/n 47011 Valladolid Spain School of Physics Trinity College Dublin College green Dublin 2 Ireland

Continuous hydrothermal synthesis was highlighted in a recent rev.ew as an enabling technology for the production of nanoparticles. In recent years, it has been shown to be a suitable reaction medium for the synthesis of a wide range of nanomaterials. Many single and complex nanomaterials such as metals, metal oxides, doped oxides, carbonates, sulfides, hydroxides, phosphates, and metal organic frameworks can be formed using continuous hydrothermal synthesis techniques. This work presents a methodology to characterize continuous hydrothermal flow systems both experimentally and numerically, and to determine the scalability of a counter current supercritical water reactor for the large scale production （〉1,000 T-year-1） of nanomaterials. Experiments were performed using a purpose-built continuous flow rig, featuring an injection loop on a metal salt feed line, which allowed the injection of a chromophoric tracer. At the system outlet, the tracer was detected using Uv.v.s absorption, which could be used to measure the residence time distribution within the reactor v.lume. Computational fluid dynamics （CFD） calculations were also conducted using a modeled geometry to represent the experimental apparatus. The performance of the CFD model was tested against experimental data, v.rifying that the CFD model accurately predicted the nucleation and growth of the nanomaterials inside the reactor.

关键词： nanoparticle computational fluid dynamics synthesis supercritical inorganics

Catalytic perfomance of rhodium chalcogen halides and rhodium chalcogenides ov.r silica supports in methane oxidativ. carbonylation

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Journal of Natural Gas Chemistry 2009年第4期18卷 399-406页

作者： S. v. v.lkov.G. R. Kosmambetov. L. B. Kharkov. O. v. shvets O. G. Yanko v. I. Gritsenko P. E. Strizhak v. I. v.rnadskii Institute of General and Inorganic Chemistry of the Ukrainian National Academy of Sciences L. v. Pisarzhev.ky Institute of Physical Chemistry of the Ukrainian National Academy of Sciences

The gas phase methane oxidativ. carbonylation was studied in the presence of molecular oxygen ov.r silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorganic media. The formation of Rh4SCl7, Rh4S9Cl2, Rh4SesCl3 and Rh3Se3Cl solids was confirmed by elemental analysis, IR absorption spectroscopy, XPS and X-ray diffraction. Silica, v.nadium-, and molybdenum-containing mesoporous molecular siev.s hav. been used as supports. It was found that productiv.ty of oxygenates （methanol, methyl acetate and acetic acid） depends mainly on the method of the catalyst preparation and the type of the support.

关键词： catalysts rhodium chalcogen halides methane oxidativ. carbonylation silica supports