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Author Yu, M.Y.; Yu, W.; Chen, Z.Y.; Zhang, J.; Yin, Y.; Cao, L.H.; Lu, P.X.; Xu, Z.Z.
Title Electron acceleration by an intense short-pulse laser in underdense plasma Type A1 Journal article
Year 2003 Publication Physics of plasmas Abbreviated Journal Phys Plasmas
Volume 10 Issue 6 Pages 2468-2474
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Electron acceleration from the interaction of an intense short-pulse laser with low density plasma is considered. The relation between direct electron acceleration within the laser pulse and that in the wake is investigated analytically. The magnitude and location of the ponderomotive-force-caused charge separation field with respect to that of the pulse determine the relative effectiveness of the two acceleration mechanisms. It is shown that there is an optimum condition for acceleration in the wake. Electron acceleration within the pulse dominates as the pulse becomes sufficiently short, and the latter directly drives and even traps the electrons. The latter can reach ultrahigh energies and can be extracted by impinging the pulse on a solid target. (C) 2003 American Institute of Physics.
Address
Corporate Author Thesis
Publisher Place of Publication Woodbury, N.Y. Editor
Language Wos 000183316500031 Publication Date 2003-05-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1070-664X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.115 Times cited 41 Open Access
Notes Approved Most recent IF: 2.115; 2003 IF: 2.146
Call Number UA @ lucian @ c:irua:103293 Serial 904
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Author Bogaerts, A.; Gijbels, R.
Title Numerical modelling of gas discharge plasmas for various applications Type A1 Journal article
Year 2003 Publication Vacuum: surface engineering, surface instrumentation & vacuum technology Abbreviated Journal Vacuum
Volume 69 Issue Pages 37-52
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Gas discharge plasmas are used for a wide range of applications. To improve our understanding about gas discharges, which is necessary to obtain good results in the various application fields, we perform numerical modelling of gas discharge plasmas. Various kinds of modelling approaches, for various types of gas discharges, are being used in our group. In this paper, some examples of this modelling work are outlined. (C) 2002 Elsevier Science Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000180739000006 Publication Date 2002-12-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0042-207X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.53 Times cited 16 Open Access
Notes Approved Most recent IF: 1.53; 2003 IF: 0.612
Call Number UA @ lucian @ c:irua:40194 Serial 2401
Permanent link to this record
 
 
Author Yandouzi, M.; Pauwels, B.; Schryvers, D.; Van Swygenhoven, H.; Van Tendeloo, G.
Title Structural characterization of nanostructured Ni3Al processed by inert gas condensation Type A1 Journal article
Year 2003 Publication Diffusion and defect data : solid state data : part A : defect and diffusion forum Abbreviated Journal
Volume 213 Issue 2 Pages 19-30
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) High-resolution transmission electron microscopy was performed on compacted Ni(3)Al nanostructured material prepared by the inert gas condensation technique. From electron diffraction data an incomplete L1(2) ordering of the crystallites is observed in the free particles as well as in the room temperature compacted samples. However, a completely ordered L1(2) structure with much bigger and well-defined crystallites exhibiting several defects is observed in material compacted and annealed at 773 K. Sharp crystallite boundaries as well as amorphous material and voids are observed in between crystallites in all samples, the former being dominant in the annealed material, the latter in the as-prepared one.
Address
Corporate Author Thesis
Publisher Place of Publication Aedermannsdorf Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1012-0386 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:94868 Serial 3221
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Author de Gryse, O.; Vanhellemont, J.; Clauws, P.; Lebedev, O.; van Landuyt, J.; Simoen, E.; Claeys, C.
Title A novel approach to analyse FTIR spectra of precipitates in boron-doped silicon Type A1 Journal article
Year 2003 Publication Physica: B : condensed matter T2 – 22nd International Conference on Defects in Semiconductors (ICDS-22), JUL 28-AUG 01, 2003, UNIV AARHUS, AARHUS, DENMARK Abbreviated Journal Physica B
Volume 340 Issue Pages 1013-1017
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Infrared absorption spectra of composite precipitates are analysed with a modified Day-Thorpe algorithm, assuming a precipitated phase consisting of a mixture of two components with known optical properties. Additional constraints are introduced when solving the model equations by using a priori knowledge making the algorithm more reliable. It is shown that this novel approach allows determining both morphology and composition of precipitates. The method is applied to characterise oxide precipitates in boron-doped silicon. The results indicate that for the resistivity range above 60 mOmegacm, the precipitated phase is most probably SiO1.17+/-0.14, while for resistivities below 20 mOmega cm, precipitates consist of a SiO2/B2O3 composite with a large volume fraction of B(2)0(3) (up to 40% for 8 mOmegacm material). (C) 2003 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000188300200213 Publication Date 2003-11-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4526; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.386 Times cited 4 Open Access
Notes Approved Most recent IF: 1.386; 2003 IF: 0.908
Call Number UA @ lucian @ c:irua:103784 Serial 25
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Author van Renterghem, W.; Schryvers, D.; van Landuyt, J.; van Roost, C.; de Keyzer, R.
Title The influence of crystal thickness on the image tone Type A1 Journal article
Year 2003 Publication Journal of imaging science Abbreviated Journal J Imaging Sci Techn
Volume 47 Issue 2 Pages 133-138
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) It is known that the neutral image tone of a developed photographic film becomes brownish when the thickness of the original silver halide tabular crystals is reduced. We investigate by electron microscopy to what extent the silver filament structure has changed and how it induces the shift in image tone. Therefore, two samples of AgBr {111} tabular crystals with average thicknesses of 160 nm and 90 nm respectively, are compared. It is shown that the dimensions and defect structure of the filaments are comparable, but that the 90 nm crystals result in a more widely spaced structure, which explains the shift in image tone on a qualitative level. The influence of the addition of an image toner, i.e., phenylmercaptotetrazole, on the filament structure is also investigated. An even more open filament structure of longer, but smaller filaments was observed.
Address
Corporate Author Thesis
Publisher Place of Publication Springfield, Va Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 8750-9237; 1062-3701 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 0.348 Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:48384 Serial 1619
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Author Baelus, B.J.; Peeters, F.M.
Title Multiply connected mesoscopic superconductors Type A1 Journal article
Year 2003 Publication Modern physics letters B T2 – 3rd International Conference on Modern Problems in Superconductivity, SEP 09-14, 2002, YALTA, UKRAINE Abbreviated Journal Mod Phys Lett B
Volume 17 Issue 10-12 Pages 527-536
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) Multiply connected mesoscopic: superconductors are considered within the framework of the nonlinear Ginzburg-Landau theory. The two coupled nonlinear equations are solved numerically and we investigated the properties of a superconducting ring, two concentric rings, and an asymmetric ring. We find that (i) for a mesoscopic superconducting ring the flux through the hole is not quantized, (ii) two concentric mesoscopic superconducting rings are magnetically coupled and the interaction energy increases with increasing sample thickness, and (iii) in asymmetric rings, a stationary phase slip state is predicted.
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Corporate Author Thesis
Publisher World scientific publ co pte ltd Place of Publication Singapore Editor
Language Wos 000184303900016 Publication Date 2003-07-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-9849;1793-6640; ISBN Additional Links UA library record; WoS full record
Impact Factor 0.617 Times cited Open Access
Notes Approved Most recent IF: 0.617; 2003 IF: 0.461
Call Number UA @ lucian @ c:irua:103810 Serial 2236
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Author Ivanov, V.A.; Krstajic, P.M.; Peeters, F.M.; Fleurov, V.; Kikoin, K.
Title On the nature of ferromagnetism in dilute magnetic semiconductors : GaAs:Mn and GaP:Mn Type A1 Journal article
Year 2003 Publication Journal of magnetism and magnetic materials T2 – 2nd Moscow International Symposium on Magnetism (MISM 2001), JUN 20-24, 2001, MOSCOW STATE UNIV, MOSCOW, RUSSIA Abbreviated Journal J Magn Magn Mater
Volume 258 Issue Pages 237-240
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) On the basis of a simplified Hamiltonian for transition metal impurities in diluted magnetic semiconductors (DMS), the nature of ferromagnetism in p-type III-V DMS are investigated. Ferromagnetism is governed by the Anderson-Hubbard parameter for 3d electrons of Mn2+ and their strong hybridization with the hole carriers in the semiconducting medium. The origin of ferromagnetism in these materials has similarity with the Zener mechanism. From the energetically preferable parallel orientation of Mn spins the Curie temperature is calculated for GaAs:Mn. (C) 2002 Published by Elsevier Science B.V.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000181702000062 Publication Date 2003-03-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-8853; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.63 Times cited 10 Open Access
Notes Approved Most recent IF: 2.63; 2003 IF: 0.910
Call Number UA @ lucian @ c:irua:103311 Serial 2442
Permanent link to this record
 
 
Author Rosenauer, A.; Gerthsen, D.; Van Aert, S.; van Dyck, D.; den Dekker, A.J.
Title Present state of the composition evaluation of ternary semiconductor nanostructures by lattice fringe analysis Type A1 Journal article
Year 2003 Publication Institute of physics conference series Abbreviated Journal
Volume Issue 180 Pages 19-22
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Abstract (up) Semiconductor heterostructures are used for the fabrication of optoelectronic devices. Performance of such devices is governed by their chemical morphology. The composition distribution of quantum wells and dots is influenced by kinetic growth processes which are not understood completely at present. To obtain more information about these effects, methods for composition determination with a spatial resolution at a near atomic scale are necessary. In this paper we focus on the present state of the composition evaluation by the lattice fringe analysis (CELFA) technique and explain the basic ideas, optimum imaging conditions, precision and accuracy.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7503-0979-2 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:95118 Serial 2710
Permanent link to this record
 
 
Author Lazoryak, B.I.; Baryshnikova, O.V.; Stefanovich, S.Y.; Malakho, A.P.; Morozov, V.A.; Belik, A.A.; Leonidov, I.A.; Leonidova, O.N.; Van Tendeloo, G.
Title Ferroelectric and ionic-conductive properties of nonlinear-optical vanadate, Ca9Bi(VO4)7 Type A1 Journal article
Year 2003 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 15 Issue 15 Pages 3003-3010
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Structural, chemical, and physical properties of whitlockite-type Ca9Bi(VO4)(7) were studied by X-ray powder diffraction (XRD), electron diffraction (ED), second-harmonic generation (SHG), thermogravimetry, differential scanning calorimetry, dielectric, and electrical-conductivity measurements. A new phase-transition of the ferroelectric type was found in Ca9Bi(VO4)(7) with a transition temperature, T-c of 1053 +/- 3 K. The polar phase, beta-Ca9Bi(VO4)(7), is stable below T-c down to at least 160 K. The centrosymmetric beta'-phase is stable above T-c up to 1273 +/- 5 K. Above 1273 K, it decomposes to give BiVO4 and whitlockite-type solid solutions of Ca9+1.5xBi1-x(VO4)(7). The beta<---->beta' phase transition is reversible and of second order. Electrical conductivity of beta'-Ca9Bi(VO4)(7) is rather high (sigma = 0.6 x 10(-3) S/cm at 1200 K) and obeys the Arrhenius law with an activation energy of 1.0 eV. Structure parameters of Ca9Bi(VO4)(7) are refined by the Rietveld method from XRD data measured at room temperature (space group R3c; Z = 6; a = 10.8992(1) Angstrom, c = 38.1192(4) Angstrom, and V = 3921.6(1) Angstrom(3); R-wp = 3.06% and R-p = 2.36%). Bi3+ ions together with Ca2+ ions are statistically distributed among the M1, M2, M3, and M5 sites. Ca9Bi(VO4)(7) has a SHG efficiency of about 140 times that of quartz. Through the powder SHG measurements, we estimated the nonlinear optical susceptibility, Digital, at about 6.1-7.2 pm/V. This value for Ca9Bi(VO4)(7) is comparable with that for known nonlinear optical materials such as LiNbO3 and LiTaO3.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000184379900024 Publication Date 2003-07-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 51 Open Access
Notes Iup V-1; Dwtc Approved Most recent IF: 9.466; 2003 IF: 4.374
Call Number UA @ lucian @ c:irua:103284 Serial 1179
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Author Abakumov, A.M.; Alekseeva, A.M.; Rozova, M.G.; Antipov, E.V.; Lebedev, O.I.; Van Tendeloo, G.
Title Ordering of tetrahedral chains in the Sr2MnGaO5 brownmillerite Type A1 Journal article
Year 2003 Publication Journal of solid state chemistry Abbreviated Journal J Solid State Chem
Volume 174 Issue 2 Pages 319-328
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Tetrahedral chain ordering in the Sr2MnGaO5 structure is studied using electron diffraction (ED) and high-resolution electron microscopy. The ED patterns show the presence of satellite reflections, which indicate a commensurately modulated structure with a = 5.4056(8) Angstrom b 16.171(3) Angstrom, c = 5.5592(7) Angstrom, q – 1/2c*, superspace group Immma(00gamma,)s00. The Superstructure arises due to ordering of the two types of symmetry related tetrahedral chains (L and R) according to a ... LRLR ... sequence, where L and R chains alternate along the c-axis within the same (GaO) layer. Numerous defects at different structural levels were observed, comprising interleaving L and R chains, violation of the ... LRLR ... chain sequence within one layer, different stacking modes of the ... LRLR ... ordered layers with subsequent alternation of blocks of different width along the h-axis of the brownmillerite subcell and island fragmentation of the modulated superstructure. By in situ heating ED experiments it is found that the long-range ordering of the tetrahedral chains is stable tip to 665degreesC and is completely suppressed at 905degreesC. (C) 2003 Elsevier Inc. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000185180500011 Publication Date 2003-07-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-4596; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.299 Times cited 34 Open Access
Notes Approved Most recent IF: 2.299; 2003 IF: 1.413
Call Number UA @ lucian @ c:irua:94846 Serial 2506
Permanent link to this record
 
 
Author Boullay, P.; Schryvers, D.; Ball, J.M.
Title Nano-structures at martensite macrotwin interfaces in Ni65Al35 Type A1 Journal article
Year 2003 Publication Acta materialia Abbreviated Journal Acta Mater
Volume 51 Issue 5 Pages 1421-1436
Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Abstract (up) The atomic configurations at macrotwin interfaces between microtwinned martensite plates in Ni65Al35 material are investigated using transmission electron microscopy. The observed structures are interpreted in view of possible formation mechanisms for these interfaces. A distinction is made between cases in which the microtwins, originating from mutually perpendicular {110} austenite planes, enclose a final angle larger or smaller than 90degrees. Two different configurations, a crossing and a step type are described. Depending on the actual case, tapering, bending and tip splitting of the smaller microtwinvariants are observed. The most reproducible deformations occur in a region of approximately 5-10 nm width around the interface while a variety of structural defects are observed further away from the interface. These structures and deformations are interpreted in terms of the coalescence of two separately nucleated microtwinned martensite plates and the need to accommodate remaining stresses. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000181677700018 Publication Date 2003-03-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1359-6454; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.301 Times cited 31 Open Access
Notes Approved Most recent IF: 5.301; 2003 IF: 3.059
Call Number UA @ lucian @ c:irua:48364 Serial 2248
Permanent link to this record
 
 
Author Blumenau, A.T.; Jones, R.; Frauenheim, T.; Willems, B.; Lebedev, O.I.; Van Tendeloo, G.; Fisher, D.; Martineau, P.M.
Title Dislocations in diamond : dissociation into partials and their glide motion Type A1 Journal article
Year 2003 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 68 Issue 1 Pages 014115-14119
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The dissociation of 60degrees and screw dislocations in diamond is modeled in an approach combining isotropic elasticity theory with ab initio-based tight-binding total-energy calculations. Both dislocations are found to dissociate with a substantial lowering of their line energies. For the 60degrees dislocation, however, an energy barrier to dissociation is found. We investigate the core structure of a screw dislocation distinguishing “shuffle,” “mixed,” and “glide” cores. The latter is found to be the most stable undissociated screw dislocation. Further, the glide motion of 90degrees and 30degrees partials is discussed in terms of a process involving the thermal formation and subsequent migration of kinks along the dislocation line. The calculated activation barriers to dislocation motion show that the 30degrees partial is less mobile than the 90degrees partial. Finally, high-resolution electron microscopy is performed on high-temperature, high-pressure annealed natural brown diamond, allowing the core regions of 60degrees dislocations to be imaged. The majority of dislocations are found to be dissociated. However, in some cases, undissociated 60degrees dislocations were also observed.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000184582900050 Publication Date 2003-08-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 39 Open Access
Notes Approved Most recent IF: 3.836; 2003 IF: NA
Call Number UA @ lucian @ c:irua:103800 Serial 734
Permanent link to this record
 
 
Author Goemans, M.; Clarysse, P.; Joannès, J.; de Clercq, P.; Lenaerts, S.; Matthys, K.; Boels, K.
Title Catalytic Nox reduction with simultaneous dioxin and furan oxidation Type A1 Journal article
Year 2003 Publication Chemosphere Abbreviated Journal Chemosphere
Volume 50 Issue 4 Pages 489-497
Keywords A1 Journal article
Abstract (up) The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/N m3 has been demonstrated. At the same time, NOx- and CO-emissions are reduced by 90% and 20% to about 50 mg/N m3 and below 10 mg/N m3, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000180078200004 Publication Date 2002-12-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0045-6535; 1879-1298 ISBN Additional Links UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles
Impact Factor 4.208 Times cited Open Access
Notes Approved Most recent IF: 4.208; 2003 IF: 1.904
Call Number UA @ admin @ c:irua:82010 Serial 5932
Permanent link to this record
 
 
Author Bogaerts, A.; Grozeva, M.
Title Effect of helium/argon gas ratio in a He-Ar-Cu+ IR hollow-cathode discharge laser : modeling study and comparison with experiments Type A1 Journal article
Year 2003 Publication Applied physics B : lasers and optics Abbreviated Journal Appl Phys B-Lasers O
Volume 76 Issue 3 Pages 299-306
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) The He-Ar-Cu+ IR laser operates in a hollow-cathode discharge, typically in a mixture of helium with a few-% Ar. The population inversion of the Cu+ ion levels, responsible for laser action, is attributed to asymmetric charge transfer between He+ ions and sputtered Cu atoms. The Ar gas is added to promote sputtering of the Cu cathode. In this paper, a hybrid modeling network consisting of several different models for the various plasma species present in a He-Ar-Cu hollow-cathode discharge is applied to investigate the effect of Ar concentration in the gas mixture on the discharge behavior, and to find the optimum He/Ar gas ratio for laser operation. It is found that the densities of electrons, Ar+ ions, Ar-m* metastable atoms, sputtered Cu atoms and Cu+ ions increase upon the addition of more Ar gas, whereas the densities of He+ ions, He-2(+) ions and He-m* metastable atoms drop considerably. The product of the calculated Cu atom and He+ ion densities, which determines the production rate of the upper laser levels, and hence probably also the laser output power, is found to reach a maximum around 1-5% Ar addition. This calculation result is compared to experimental measurements, and reasonable agreement has been reached.
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000182758000017 Publication Date 2004-03-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0946-2171;1432-0649; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.696 Times cited 6 Open Access
Notes Approved Most recent IF: 1.696; 2003 IF: 2.012
Call Number UA @ lucian @ c:irua:104125 Serial 812
Permanent link to this record
 
 
Author Horvath, Z.E.; Biro, L.P.; Van Tendeloo, G.; Tondeur, C.; Bister, G.; Pierard, N.; Fonseca, A.; Nagy, J.B.
Title Optimization of the amount of catalyst and reaction time in single wall nanotube production Type A1 Journal article
Year 2003 Publication Diffusion and defect data : solid state data : part B : solid state phenomena Abbreviated Journal Solid State Phenom
Volume 94 Issue Pages 271-274
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The influence of the amount of catalyst and the reaction time on the quantity and quality of catalytically grown single wall carbon nanotubes (SWNT) was investigated. The aim was to optimize some of the SWNT growth parameters using TEM and HRTEM. The thickness of catalyst layer influences the synthesis of the nanotube because the gas composition can differ between top and bottom. Microscopic investigation of the grown SWNT samples showed that the thicker the catalyst layer the lower relative nanotube content, so the deeper parts of the catalyst layer are less effective: The optimum time for the reaction was found to be 10 minutes. This may be understood assuming that nanotube growth needs an initial incubation time while the activity of the catalyst decreases steadily until the nariotube growth stops.
Address
Corporate Author Thesis
Publisher Place of Publication Vaduz Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1012-0394; 1662-9779 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:94860 Serial 2490
Permanent link to this record
 
 
Author Chen, Z.; Feng, X.; Xu, Y.; Yu, M.Y.
Title Optical bistability and multistability in four-level systems Type A1 Journal article
Year 2003 Publication Physica scripta Abbreviated Journal Phys Scripta
Volume 68 Issue 3 Pages 199-204
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) The optical behavior of a four-level system in a ring cavity driven by two coherent laser fields is studied. One laser field is treated as the incident field and the other the control field, respectively. It is found that there is optical transparency when the difference between the two frequency detunings of the incident and control fields from the corresponding atomic transition frequencies is zero. Optical bistability can be produced and controlled by increasing the magnitude of the frequency difference. The bistable hysteresis becomes larger when the frequency difference is increased. Further increase of the latter can lead to onset of multistability.
Address
Corporate Author Thesis
Publisher Place of Publication Stockholm Editor
Language Wos 000185204400005 Publication Date 2003-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949;1402-4896; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.28 Times cited 8 Open Access
Notes Approved Most recent IF: 1.28; 2003 IF: 0.688
Call Number UA @ lucian @ c:irua:94844 Serial 2471
Permanent link to this record
 
 
Author Ferreira, W.P.; Matulis, A.; Farias, G.A.; Peeters, F.M.
Title Structure and correlations in two-dimensional classical artificial atoms confined by a Coulomb potential Type A1 Journal article
Year 2003 Publication Physical review : E : statistical, nonlinear, and soft matter physics Abbreviated Journal Phys Rev E
Volume 67 Issue 4Part 2 Pages 046601-46608
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) The ordering of N equally charged particles (-e) moving in two dimensions and confined by a Coulomb potential, resulting from a displaced positive charge Ze is discussed. This is a classical model system for atoms. We obtain the configurations of charged particles which, depending on the value of N and Z, may result in ring structures, hexagonal-type configurations, and for N/Z approximate to 1 in an inner structure of particles which is separated by an outer ring of particles. For N/Z << 1, the Hamiltonian of the parabolic confinement case is recovered. For N/Z approximate to 1, the configurations are very different from those found in the case of a parabolic confinement potential. A hydrodynamic analysis is presented in order to highlight the correlations effects.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication Woodbury (NY) Editor
Language Wos 000182825400087 Publication Date 2003-04-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1063-651X;1095-3787; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 14 Open Access
Notes Approved Most recent IF: 2.366; 2003 IF: 2.202
Call Number UA @ lucian @ c:irua:104123 Serial 3273
Permanent link to this record
 
 
Author Antipov, E.V.; Khasanova, N.R.; Pshirkov, J.S.; Putilin, S.N.; Bougerof, C.; Lebedev, O.I.; Van Tendeloo, G.; Baranov, A.; Park, Y.W.
Title The superconducting bismuth-based mixed oxides Type A1 Journal article
Year 2003 Publication Journal of low temperature physics T2 – International Conference on Physics and Chemistry of Molecular and Oxide, Superconductors (MOS2002), AUG 13-18, 2002, HSINCHU, TAIWAN Abbreviated Journal J Low Temp Phys
Volume 131 Issue 3-4 Pages 575-587
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The present paper describes the synthesis, characterization of mixed-valence bismuthates with 3- or 2-dimensional perovskite-like structures and structural criteria that influence superconductivity in these compounds. Single-phase samples of Sr1-xKxBiO3 were prepared for the broad range of K-content: 0.25 less than or equal to x less than or equal to 0.65. For these bismuthates the symmetry of the structure changes from monoclinic to orthorhombic and finally to tetragonal upon increasing the K-content thus resulting in the decrease of the Bi-O distances and reduction of the network distortions. Superconductivity with maximum T-c = 12K exists in the narrow range (x approximate to 0.5 – 0.6) within the stability field of the tetragonal phase (0.33 less than or equal to x less than or equal to 0.65), when the 3-dimensional octahedral framework has close to the ideal perovskite structure arrangement. At the same time compositions with close to optimal Bi-valence (x = 0.33 and 0.43) do not show any sign of superconductivity, probably, due to structural distortions. The layered type (BaK)(3)Bi2O7 and (Ba,K)(2)BiO4 bismuthates belonging to the A(n+1)B(n)O(3n+1) homologous series were investigated Buckling of the (BiO2) layers in the structure of the n = 2 member was revealed The formation of the n=1 bismuthate was found by Electron Microscopy and X-ray powder diffraction studies. Both types of compounds are considered to be possible candidates for new superconducting materials among bismuthates.
Address
Corporate Author Thesis
Publisher Place of Publication New York Editor
Language Wos 000181768000061 Publication Date 2003-04-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.3 Times cited 3 Open Access
Notes Approved Most recent IF: 1.3; 2003 IF: 1.171
Call Number UA @ lucian @ c:irua:102803 Serial 3597
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Author Chang, K.; Xia, J.B.; Peeters, F.M.
Title Magnetic field tuning of the effective g factor in a diluted magnetic semiconductor quantum dot Type A1 Journal article
Year 2003 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 82 Issue 16 Pages 2661-2663
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) The spin interaction and the effective g factor of a magnetic exciton (ME) are investigated theoretically in a diluted magnetic semiconductor (DMS) quantum dot (QD), including the Coulomb interaction and the sp-d exchange interaction. At low magnetic field, the ME energy decreases rapidly with increasing magnetic field and saturates at high magnetic field for high Mn concentration. The ground state of the ME exhibits an interesting crossing behavior between sigma(+)-ME and sigma(-)-ME for low Mn concentration. The g(ex) factor of the ME in a DMS QD displays a monotonic decrease with increasing magnetic field and can be tuned to zero by an external magnetic field. (C) 2003 American Institute of Physics.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000182258800037 Publication Date 2003-04-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 56 Open Access
Notes Approved Most recent IF: 3.411; 2003 IF: 4.049
Call Number UA @ lucian @ c:irua:103301 Serial 1878
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Author Piacente, G.; Schweigert, I.V.; Betouras, J.J.; Peeters, F.M.
Title Structural properties and melting of a quasi-one dimensional classical Wigner crystal Type A1 Journal article
Year 2003 Publication Solid state communications Abbreviated Journal Solid State Commun
Volume 128 Issue 2-3 Pages 57-61
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) The structural and melting properties of a quasi-one dimensional system of charged particles, interacting through a screened Coulomb potential are investigated. Depending on the density and the screening length, the system crystallizes in different lattice structures. The structural phase transitions between them are of first or second order. The melting of the system is studied through Monte Carlo simulations and reentrant behavior as a function of density is observed as well as evidence of anisotropic melting. (C) 2003 Published by Elsevier Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000185533100004 Publication Date 2003-08-12
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.554 Times cited 9 Open Access
Notes Approved Most recent IF: 1.554; 2003 IF: 1.602
Call Number UA @ lucian @ c:irua:102790 Serial 3253
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Author Nikolaev, A.V.; Michel, K.H.
Title Symmetry lowering at the structural phase transitions in NpO2 and UO2 Type A1 Journal article
Year 2003 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B
Volume 68 Issue 5 Pages 054112-054112,7
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) The structural phase transitions with electric-quadrupole long-range order in NpO2 (Fm (3) over barm-->Pn (3) over barm) and UO2 (Fm (3) over barm-->Pa (3) over bar) are analyzed from a group theoretical point of view. In both cases, the symmetry lowering involves three quadrupolar components belonging to the irreducible representation T-2g (Gamma(5)) of O-h and condensing in a triple-q structure at the X point of the Brillouin zone. The Pa (3) over bar structure is close to Pn (3) over barm, but allows for oxygen displacements. The Pa (3) over bar ordering leads to an effective electrostatic attraction between electronic quadrupoles while the Pn (3) over barm ordering results in a repulsion between them. It is concluded that the Pn (3) over barm structure can be stabilized only through some additional process such as strengthening of the chemical bonding between Np and O. We also derive the relevant structure-factor amplitudes for Pn (3) over barm and Pa (3) over bar, and the effect of domains on resonant x-ray scattering experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000185240100038 Publication Date 2003-08-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 15 Open Access
Notes Approved Most recent IF: 3.836; 2003 IF: NA
Call Number UA @ lucian @ c:irua:94847 Serial 3405
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Author Nistor, L.C.; Richard, O.; Zhao, O.; Bender, H.; Stesmans, A.; Van Tendeloo, G.
Title A microstructural study of the thermal stability of atomic layer deposited Al2O3 thin films Type A1 Journal article
Year 2003 Publication Institute of physics conference series T2 – Microscopy of semiconducting materials Abbreviated Journal
Volume Issue Pages 397-400
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) The thermal stability of amorphous Al2O3 films (similar to8 and 80 nut thick) deposited by atomic layer deposition on HF-last and thin SiO2 covered (001) Si substrates is studied by transmission electron microscopy. The layers are in- and ex-situ annealed in the same temperature range.
Address
Corporate Author Thesis
Publisher Iop Place of Publication Cambridge Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7503-0979-2 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:54860 Serial 2048
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Author Lenaerts, J.; van Vaeck, L.; Gijbels, R.
Title Secondary ion formation of low molecular weight organic dyes in time-of-flight static secondary ion mass spectrometry Type A1 Journal article
Year 2003 Publication Rapid communications in mass spectrometry Abbreviated Journal Rapid Commun Mass Sp
Volume 17 Issue 18 Pages 2115-2124
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) Time-of-flight static secondary ion mass spectrometry (TOF-S-SIMS) was used to characterize thin layers of oxy- and thiocarbocyanine dyes on Ag and Si. Apart from adduct ions a variety of structural fragment ions were detected for which a fragmentation pattern is proposed. Peak assignments were confirmed by comparing spectra of dyes with very similar structures. All secondary ions were assigned with a mass accuracy better than 50 ppm. The intensity of molecular ions as well as fragment ions has been studied as a function of the type of organic dye, the substrate, the layer thickness and the type of primary ion. A large yield difference of two orders of magnitude was observed between the precursor ions of cationic carbocyanine dyes and the protonated molecules of the anionic dyes. Fragment ions, on the other hand, yielded similar intensities for both types of dye. As the dye layers deposited on an Ag substrate yielded higher secondary ion intensities than those deposited on a Si substrate, the Ag metal clearly acts as a promoting agent for secondary ion formation. The effect was more pronounced for precursor signals than for fragment ions. The promoting effect decreased as the deposited layer thickness of the organic dye layer was increased. Copyright (C) 2003 John Wiley Sons, Ltd.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000185230400014 Publication Date 2003-09-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0951-4198;1097-0231; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.998 Times cited 10 Open Access
Notes Approved Most recent IF: 1.998; 2003 IF: 2.789
Call Number UA @ lucian @ c:irua:104132 Serial 2958
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Author Bals, S.; Van Tendeloo, G.; Rijnders, G.; Huijben, M.; Leca, V.; Blank, D.H.A.
Title Transmission electron microscopy on interface engineered superconducting thin films Type A1 Journal article
Year 2003 Publication IEEE transactions on applied superconductivity Abbreviated Journal Ieee T Appl Supercon
Volume 13 Issue 2:3 Pages 2834-2837
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) Transmission electron microscopy is used to evaluate different deposition techniques, which optimize the microstructure and physical properties of superconducting thin films. High-resolution electron microscopy proves that the use of an YBa2Cu2Ox buffer layer can avoid a variable interface configuration in YBa2Cu3O7-delta thin films grown on SrTiO3. The growth can also be controlled at an atomic level by, using sub-unit cell layer epitaxy, which results in films with high quality and few structural defects. Epitaxial strain in Sr0.85La0.15CuO2 infinite layer thin films influences the critical temperature of these films, as well as the microstructure. Compressive stress is released by a modulated or a twinned microstructure, which eliminates superconductivity. On the other hand, also tensile strain seems to lower the critical temperature of the infinite layer.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000184242400101 Publication Date 2003-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1051-8223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 13 Open Access
Notes Iuap V-1; Fwo Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:103292 Serial 3712
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Author Schalm, O.; Janssens, K.; Caen, J.
Title Characterization of the main causes of deterioration of grisaille paint layers in 19th C. stained-glass windows by J.-B. Capronnier Type A1 Journal article
Year 2003 Publication Spectrochimica acta: part B : atomic spectroscopy Abbreviated Journal Spectrochim Acta B
Volume 58 Issue 4 Pages 589-607
Keywords A1 Journal article; Art; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract (up) Twenty-seven glass fragments containing dark coloured grisaille paint layers of different qualities were collected from ten windows of the cathedral St. Michael & St. Gudule in Brussels (Belgium). The windows were made by J.-B. Capronnier (18141891) and cover the period between 1843 and 1878. The samples were cross-sectioned and examined in an electron microscope. Grisaille paint layers are not homogeneous and therefore, it is not meaningful to characterize them in terms of their average composition. Instead, parameters such as granularity, the number of residual gas bubbles per running millimetre of paint, the type of pigments, and the thickness of the paint layer were used to characterize them. The microscopic morphology allows a classification of the grisaille paint layers in four groups, every group associated with a quality level. Moreover, the main causes of the accelerated degradation of some of these paint layers could be explained. The classification made it possible to distinguish two periods in the work of Capronnier: (1) the early period (18431848) is characterized by the presence of either single granular paint layers or of double-layered systems consisting of a granular paint layer on top of a well-melted paint layer. The granular grisaille paint layers tend to pulverize; (2) the later period (18481878) is characterized by the presence of only well-vitrified paint layers. No sign of deterioration was found on the well-vitrified paint layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000182744200002 Publication Date 2003-04-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0584-8547; 0038-6987 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.241 Times cited Open Access
Notes Approved Most recent IF: 3.241; 2003 IF: 2.361
Call Number UA @ admin @ c:irua:41208 Serial 5505
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Author de Witte, H.; Conard, T.; Vandervorst, W.; Gijbels, R.
Title Ion-bombardment artifact in TOF-SIMS analysis of ZrO2/SiO2/Si stacks Type A1 Journal article
Year 2003 Publication Applied surface science Abbreviated Journal Appl Surf Sci
Volume 203 Issue Pages 523-526
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract (up) We analyzed ultra-thin ZrO2/SiO2/Si gate dielectrics under post-deposition anneals in dry O-2 at temperatures from 500 to 700 degreesC. TOF-SIMS profiling of ZrO2/SiO2/Si stacks is hampered by many sputter induced artifacts. The depletion of oxygen leads to a decrease in SIMS intensities. However, preferential sputtering is accompanied by transport of the depleted species towards the surface. Due to recoil implantation oxygen gets piled-up near the ZrO2/SiO2 interface. Either normal or radiation-enhanced diffusion transports oxygen back to the surface. Simultaneously also segregation of zirconium towards and through the interface is observed, resulting in a large zirconium tail in the underlying silicon substrate. (C) 2002 Elsevier Science B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Elsevier science bv Place of Publication Amsterdam Editor
Language Wos 000180527300119 Publication Date 2002-12-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited 15 Open Access
Notes Approved Most recent IF: 3.387; 2003 IF: 1.284
Call Number UA @ lucian @ c:irua:51975 Serial 1743
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Author Anisimovas, E.; Peeters, F.M.
Title Few-particle states in coupled electron-hole quantum dots Type P1 Proceeding
Year 2003 Publication Functions II Abbreviated Journal
Volume Issue Pages 330-337
Keywords P1 Proceeding; Condensed Matter Theory (CMT)
Abstract (up) We apply the exact diagonalization technique to calculate the ground and excited states of a bipolar artificial molecule composed of two vertically coupled quantum dots containing different types of carriers electrons and holes in equilibrium. In this system, the magnetic field tunes the relative role of intra-dot Coulomb interaction while the inter-dot separation sets the strength of inter-dot correlations. We find an intricate pattern of the switching of the ground-state angular momentum with increasing magnetic field and a rearrangement of approximate single-particle levels as a function of the inter-dot coupling strength.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000229502400029 Publication Date 2007-11-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:103838 Serial 1186
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Author Krstajic, P.M.; Ivanov, V.A.; Peeters, F.M.; Fleurov, V.; Kikoin, K.
Title Ferromagnetism in Mn-doped GaAs : the kinematic exchange Type A1 Journal article
Year 2003 Publication Journal of superconductivity T2 – PASPS Conference 2002, JUL, 2002, WURZBURG, GERMANY Abbreviated Journal J Supercond
Volume 16 Issue 1 Pages 111-113
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract (up) We developed a microscopic model in order to describe the onset of ferromagnetism (FM) in GaAs:Mn. The proposed kinematic mechanism bears resemblances with the Zener exchange. The calculated Curie temperature for GaAs: Mn is in good agreement with available experimental data of the Curie temperature as a function of the manganese concentration.
Address
Corporate Author Thesis
Publisher Place of Publication New York, N.Y. Editor
Language Wos 000182060400027 Publication Date 2003-06-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0896-1107; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 2 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:103314 Serial 1183
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Author Somsen, C.; Wassermann, E.F.; Kästner, J.; Schryvers, D.
Title Precursor phenomena in a quenched and aged Ni52Ti48 shape memory alloy Type A1 Journal article
Year 2003 Publication Journal de physique: 4 T2 – 10th International Conference on Martensitic Transformations, JUN 10-14, 2002, ESPOO, FINLAND Abbreviated Journal J Phys Iv
Volume 112 Issue Part 2 Pages 777-780
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract (up) We measured the electrical resistivity R(T) and specific heat C-p(T) between room temperature (RT) and 4.2 K as well as the microstructure by transmission electron microscopy (TEM) of a Ni-52 Ti-48 SMA quenched from 1000degreesC (B2-Phase range) to RT and then annealed for 1h at T=380degreesC, 550degreesC and 650degreesC. In the “as quenched” and the “650degreesC annealed” state no martensitic transformations (MT's) occur. The diffraction patterns show faint reflections originating from coherent Ni4Ti3 precipitates in an early state of formation. Additional reflections of the type 1/2 <110>, 1/2 <111> and 1/3 <110> result from various lattice displacement waves, which are precursors of the MT's to the B19' and R-phase, respectively. Indeed, high resolution TEM micrographs of the [001] zone of the “as quenched” sample reveal transverse 1/2 <110> <110> lattice displacement waves, precursors of the B19' martensite. The coherent Ni4Ti3 precipitates, homogeneously distributed on a small length scale, binder the MT's in the “as quenched” and the “650degreesC annealed” state, and thus only the precursors appear. When annealed at T=380degreesC, however, coherent Ni4Ti3 precipitates with a length of 10nm are clearly visible in TEM. These precipitates trigger the NIT from the B2 to the R-phase on cooling, as evidenced also by anomalies in R(T) and C-p(T). Annealing at T-550degreesC leads to the well known two step MT's from the B2 to the R-phase and then into the B19'-phase. These martensitic transitions are clearly seen as additional peaks in the specific heat and anomalies in the resistance, while the “as quenched” and 650degreesC annealed samples show weak features in R(T) and C-p(T).
Address
Corporate Author Thesis
Publisher Place of Publication Les Ulis Editor
Language Wos 000186503400036 Publication Date 2008-08-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1155-4339; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 2 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:102791 Serial 2694
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Author Ivanov, V.A.; Betouras, J.J.; Peeters, F.M.
Title MgB2 : superconductivity and pressure effects Type P1 Proceeding
Year 2003 Publication Abbreviated Journal
Volume Issue Pages 35-46
Keywords P1 Proceeding; Condensed Matter Theory (CMT)
Abstract (up) We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB2. We propose experiments which lead to identification of the possible scenarios: whether both sigma- and pi-bands superconduct or sigma-alone. According to the second scenario a microscopic theory of superconducting MgB2 is proposed based on the strongly interacting or-electrons and non-correlated pi-electrons of boron ions. The kinematic and Coulomb interactions of sigma-electrons provide the superconducting state with an anisotropic gap of s(*)-wave symmetry. The critical temperature T-c has a non-monotonic dependence on the distance r between the centers of gravity of sigma- and pi-bands. The position of MgB2 on a bell-shaped curve T-c (r) is identified in the overdoped region. The derived superconducting density of electronic states is in agreement with available experimental and theoretical data. It is argued that the effects of pressure are crucial to identify the microscopic origin of superconductivity in MgB2. Possibilities for increase of T, are discussed.
Address
Corporate Author Thesis
Publisher Springer Place of Publication Dordrecht Editor
Language Wos Publication Date 0000-00-00
Series Editor Series Title Abbreviated Series Title
Series Volume 106 Series Issue Edition
ISSN 1-4020-1372-8 ISBN Additional Links UA library record; WoS full record;
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:94869 Serial 2020
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