“Electrical nonlinearity in colossal magnetoresistance manganite films: relevance of correlated polarons”. Moshnyaga V, Gehrke K, Sudheendra L, Belenchuk A, Raabe S, Shapoval O, Verbeeck J, Van Tendeloo G, Samwer K, Physical review : B : solid state 79, 134413 (2009). http://doi.org/10.1103/PhysRevB.79.134413
Abstract: The metal-insulator (MI) transition in epitaxial thin films of La0.75Ca0.25MnO3 (LCMO) is accompanied by the appearance of an intrinsic electrical nonlinearity. The latter, probed by electrical third harmonic voltage, U3, or resistance, R3=dU3/dJ, is drastically enhanced in the vicinity of the MI transition, TMI=267 K. Applied magnetic field, B=5 T, suppresses the nonlinearity, resulting in a huge nonlinear CMR3(TMI)~105%. R3 shows a peculiar low-frequency (1 kHz) dependence, R3~(-0)n, with exponent, n, changing across the MI transition from n~1,52 for TTMI to n=1 (T<TMI). The observed electrical nonlinearity in LCMO reflects the behavior of correlated polarons, the number of which dramatically enhances in the vicinity of TMI. We argued that correlated polarons, considered as electric-elastic quadrupoles, provide a nonlinear (quadratic) coupling to the electric field, yielding a third harmonic electric nonlinearity in LCMO. The reference film of La0.7Sr0.3MnO3 (LSMO), a prototypic double exchange system with second-order phase transition, is characterized as a linear metallic material in the whole range of temperatures (T=10400 K), magnetic fields (B=05 T), and frequencies (=11000 Hz).
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 28
DOI: 10.1103/PhysRevB.79.134413
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“Electrical tomography using atomic force microscopy and its application towards carbon nanotube-based interconnects”. Schulze A, Hantschel T, Dathe A, Eyben P, Ke X, Vandervorst W, Nanotechnology 23, 305707 (2012). http://doi.org/10.1088/0957-4484/23/30/305707
Abstract: The fabrication and integration of low-resistance carbon nanotubes (CNTs) for interconnects in future integrated circuits requires characterization techniques providing structural and electrical information at the nanometer scale. In this paper we present a slice-and-view approach based on electrical atomic force microscopy. Material removal achieved by successive scanning using doped ultra-sharp full-diamond probes, manufactured in-house, enables us to acquire two-dimensional (2D) resistance maps originating from different depths (equivalently different CNT lengths) on CNT-based interconnects. Stacking and interpolating these 2D resistance maps results in a three-dimensional (3D) representation (tomogram). This allows insight from a structural (e.g. size, density, distribution, straightness) and electrical point of view simultaneously. By extracting the resistance evolution over the length of an individual CNT we derive quantitative information about the resistivity and the contact resistance between the CNT and bottom electrode.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.44
Times cited: 29
DOI: 10.1088/0957-4484/23/30/305707
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“Electrically induced spin resonance fluorescence: 1: theory”. Nogaret A, Peeters FM, Physical review : B : condensed matter and materials physics 76 (2007). http://doi.org/10.1103/PhysRevB.76.075311
Abstract: We calculate the fluorescence of electron spins confined to a plane and driven into resonance by a magnetic field gradient and a constant magnetic field applied at right angles to each other. We solve the equation of motion of two-dimensional electrons in the magnetic field gradient to derive the dispersion curve of spin oscillators, the amplitude of electron oscillations, the effective magnetic field sensed by the electron spin, and the rate at which electrons are injected from an electrode into spin oscillators. We then switch on the interaction between the spin magnetic dipole and the electromagnetic field to find the fluorescence power radiated by the individual spin oscillators. The rate of radiative decay is first derived, followed by the probability of sequential photon emission whereby a series of spontaneous decays occurs at random times separated by intervals during which the spin performs Rabi oscillations. The quantum correlations between random radiative decays manifest as bursts of emission at regular intervals along the wire. We integrate all multiphoton processes to obtain an exact analytical expression for the radiated electromagnetic power. The present theory obtains all parameters of the problem including magnetodipole coupling, the particle dwell time in the magnetic field gradient, and the spin polarization of the incoming current. The output power contains a fine structure arising from the anharmonicity of electron oscillations and from nonlinear optical effects which both give satellite emission peaks at odd multiples of the fundamental frequency.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 8
DOI: 10.1103/PhysRevB.76.075311
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“Electrically induced spin resonance fluorescence : 2 : fluorescence spectra”. Nogaret A, Lambert NJ, Peeters FM, Physical Review B 76 (2007). http://doi.org/10.1103/PhysRevB.76.075312
Abstract: We model the fluorescence spectra of planar spin oscillators to find conditions that maximize spin resonance fluorescence. Spin oscillators perform Rabi oscillations under the effect of a periodic effective magnetic field caused by the winding motion of an electron in a gradient of magnetic field. We show that, despite the weak coupling of the spin magnetic dipole to the vacuum, spin oscillators excited by a direct current output a few nanowatts of microwave power, which is comparable to the best microwave sources. The large quantum efficiency relies on the combination of two effects. On the one hand, the spontaneous emission rate is enhanced by the synchronization of spin oscillators, which interact through the microwave field that they emit. On the other hand, the huge Rabi frequencies experienced by spin oscillators promote spins into upper levels of Zeeman transitions, from which a radiative cascade is triggered. We demonstrate different regimes of fluorescence which correspond to different values of the Rabi period relative to the spontaneous decay time and to the oscillator dwell time in the gradient of magnetic field. We investigate the device parameters which make these regimes experimentally accessible and find conditions that optimize microwave output. We find that microwave emission is centered around the cutoff frequency of spin oscillators. This has the advantage that the peak emission frequency may be tuned from zero continuously up to a few hundred gigahertz using an electrostatic gate. Quite remarkably for a spintronics effect, electrically induced spin resonance fluorescence does not require the injection of a spin polarized current. In fact, we show that microwave spectra are mostly independent of the incoming spin polarization except for magnetic waveguides which are shorter than a certain critical length, which we will specify.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 8
DOI: 10.1103/PhysRevB.76.075312
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“Electrochemical growth and characterization of nanostructured ZnO thin films”. Ghica C, Enculescu I, Nistor LC, Matei E, Van Tendeloo G, Journal of optoelectronics and advanced materials 10, 3237 (2008)
Abstract: ZnO is a wide band-gap (ca. 3.4 eV) semiconductor, piezoelectric, pyroelectric, biocompatible, transparent in the visible spectrum and UV light emitting material. The fabrication in 2001 of the first nanobelts of semiconductor oxide materials lead to a rapid expansion of researches concerning one dimensional nanostructures (nanotubes, nanowires, nanobelts), given their possible application in optics, optoelectronics, piezoelectricity, catalysis. Researches carried on up to date evidenced the possibility to obtain an extraordinary variety of ZnO nanostructures, in function of the experimental parameters and the used growth methods. In this work we present morphostructural results on nanostructured ZnO layers obtained by electrochemical deposition. The films have been grown on gold covered glass plates and Si wafers, in various experimental conditions such as: nature of the wetting agents, electrical polarization of the substrate (continuous, pulsed). The influence of the growth conditions on the crystalline structure and morphology of the films is revealed by scanning and transmission electron microscopy studies. The films show a variety of growth morphologies, from entangled-wires-like to honeycomb-like layers. These large-specific-surface layers will be tested as nanostructured substrates for photovoltaic cells with improved efficiency.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.449
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“Electrodeposition of Ag nanoparticles onto carbon coated TEM grids : a direct approach to study early stages of nucleation”. Ustarroz J, Gupta U, Hubin A, Bals S, Terryn H, Electrochemistry communications 12, 1706 (2010). http://doi.org/10.1016/j.elecom.2010.10.002
Abstract: An innovative experimental approach to study the electrodeposition of small nanoparticles and the early stages of electrochemical nucleation and growth is presented. Carbon coated gold TEM grids are used as substrates for the electrodeposition of silver nanoparticles so that electrochemical data, FESEM, HAADFSTEM and HRTEM data can be acquired from the same sample without the need to remove the particles from the substrate. It is shown that the real distribution of nanoparticles cannot be resolved by FESEM whereas HAADFSTEM analysis confirms that a distribution of small nanoparticles (d ≈ 12 nm) coexist with large nanoparticles corresponding to a bimodal size distribution. Besides, particles grown under the same conditions have been found to present different structures such as monocrystals, polycrystals or aggregates of smaller particles.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 4.396
Times cited: 52
DOI: 10.1016/j.elecom.2010.10.002
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“Electroluminescence spectra of an STM-tip-induced quantum dot”. Croitoru MD, Gladilin VN, Fomin VM, Devreese JT, Kemerink M, Koenraad PM, Sauthoff K, Wolter JH, Physical review : B : condensed matter and materials physics 68, 195307 (2003). http://doi.org/10.1103/PhysRevB.68.195307
Keywords: A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 4
DOI: 10.1103/PhysRevB.68.195307
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“Electron acceleration by an intense short-pulse laser in underdense plasma”. Yu MY, Yu W, Chen ZY, Zhang J, Yin Y, Cao LH, Lu PX, Xu ZZ, Physics of plasmas 10, 2468 (2003). http://doi.org/10.1063/1.1572158
Abstract: 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.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.115
Times cited: 41
DOI: 10.1063/1.1572158
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“Electron and hole states in a quantum ring grown by droplet epitaxy. Influence of the layer inside the ring opening”. Čukarić, N, Tadić, M, Peeters FM, Superlattices and microstructures 48, 491 (2010). http://doi.org/10.1016/j.spmi.2010.09.001
Abstract: The electronic structure of the conduction and valence bands of a quantum ring containing a layer inside the ring opening is modeled This structure (nanocup) consists of a GaAs nanodisk (the cup s bottom) and a GaAs nanoring (the cup s rim) which encircles the disk The whole system is embedded in an (Al Ga)As matrix and its shape resembles realistic ring structures grown by the droplet epitaxy technique The conduction-band states in the structure are modeled by the single-band effective-mass theory while the 4-band Luttinger-Kohn model is adopted to compute the valence-band states We analyze how the electronic structure of the nanocup evolves from the one of a quantum ring when the size of either the nanodisk or the nanoring is changed For that purpose (1) the width of the ring (2) the disk radius and (3) the disk height are separately varied For dimensions typical for experimentally realized structures we find that the electron wavefunctions are mainly localized inside the ring even when the thickness of the Inner layer is 90% of the ring thickness These calculations indicate that topological phenomena like the excitonic Aharonov-Bohm effect are negligibly affected by the presence of the layer inside the ring (C) 2010 Elsevier Ltd All rights reserved
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 2.123
Times cited: 9
DOI: 10.1016/j.spmi.2010.09.001
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“Electron and hole states in diluted magnetic semiconductor quantum dots”. Chang K, Li SS, Xia JB, Peeters FM, Physical review : B : condensed matter and materials physics 69, 235203 (2004). http://doi.org/10.1103/PhysRevB.69.235203
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 32
DOI: 10.1103/PhysRevB.69.235203
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“An electron and X-ray diffraction investigation of Ni1+xTe2 and Ni1+xSe2CdI2/NiAs type solid solution phases”. Norén L, Ting V, Withers RL, Van Tendeloo G, Journal of solid state chemistry 161, 266 (2001). http://doi.org/10.1006/jssc.2001.9309
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 14
DOI: 10.1006/jssc.2001.9309
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“Electron channelling based crystallography”. Van Aert S, Geuens P, van Dyck D, Kisielowski C, Jinschek JR, Ultramicroscopy 107, 551 (2007). http://doi.org/10.1016/j.ultramic.2006.04.031
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.843
Times cited: 32
DOI: 10.1016/j.ultramic.2006.04.031
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“Electron diffraction and microscopy of single-wall carbon nanotube bundles produced by different methods”. Colomer J-F, Henrard L, Lambin P, Van Tendeloo G, European physical journal : B : condensed matter and complex systems 27, 111 (2002). http://doi.org/10.1140/epjb/e20020135
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.461
Times cited: 43
DOI: 10.1140/epjb/e20020135
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“Electron diffraction effects of conical, helically wound, graphite whiskers”. Luyten W, Krekels T, Amelinckx S, Van Tendeloo G, van Dyck D, van Landuyt J, Ultramicroscopy 49, 123 (1993). http://doi.org/10.1016/0304-3991(93)90219-N
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 2.436
Times cited: 14
DOI: 10.1016/0304-3991(93)90219-N
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“Electron diffraction evidence for ordering of interstitial silver ions in silver bromide microcrystals”. Goessens C, Schryvers D, van Dyck D, van Landuyt J, de Keyzer R, Icem 13 (1994)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
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“Electron-diffraction evidence for ordering of interstitial silver ions in silver bromide microcrystals”. Goessens C, Schryvers D, van Dyck D, van Landuyt J, de Keyzer R, Physica status solidi: A 143, 277 (1994). http://doi.org/10.1002/pssa.2211430211
Abstract: The occurrence and origin of diffuse intensity contours in electron micrographs of AgBr crystals are investigated. The observations are interpreted in terms of a model, which attributes diffuse scattering to the presence of predominant atom or vacancy clusters of a particular polyhedral type. It is shown that irrespective of the crystal morphology, interstitial Ag ions order in AgBr material in clusters of finite size along 001 type planes. A different geometry of the diffuse intensity locus observed for triangular and hexagonal tabular grains is explained in terms of the different twin plane morphology of these grains.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Times cited: 7
DOI: 10.1002/pssa.2211430211
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“Electron diffraction measurement of the binding rigidity of free-standing graphene”. Kirilenko DA, Technical physics letters 39, 325 (2013). http://doi.org/10.1134/S1063785013040081
Abstract: A method for measuring the binding rigidity of free-standing graphene from the dependence of the short-wavelength spectral range of transverse structural fluctuations of a crystal is proposed. The fluctuation spectrum is measured according to the variation in electron-diffraction patterns derived in a transmission electron microscope while tilting the sample.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.771
Times cited: 3
DOI: 10.1134/S1063785013040081
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“Electron diffraction refinement of the TiNi(Fe) R-phase structure”. Schryvers D, Potapov P, Journal de physique 112, 751 (2003). http://doi.org/10.1051/jp4:2003991
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 7
DOI: 10.1051/jp4:2003991
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“Electron-diffraction structure refinement of Ni4Ti3 precipitates in Ni52Ti48”. Tirry W, Schryvers D, Jorissen K, Lamoen D, Acta crystallographica: section B: structural science 62, 966 (2006). http://doi.org/10.1107/S0108768106036457
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 30
DOI: 10.1107/S0108768106036457
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“Electron diffraction study of small bundles of single-wall carbon nanotubes with unique helicity”. Colomer J-F, Henrard L, Lambin P, Van Tendeloo G, Physical review : B : condensed matter and materials physics 64, 125425 (2001). http://doi.org/10.1103/PhysRevB.64.125425
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 31
DOI: 10.1103/PhysRevB.64.125425
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“Electron effective mass and resonant polaron effect in CdTe/CdMgTe quantum wells”. Karczewski G, Wojtowicz T, Wang Y-J, Wu X, Peeters FM, Physica status solidi: B: basic research
T2 –, 10th International Conference on II-VI Compounds, SEP 09-14, 2001, BREMEN, GERMANY 229, 597 (2002). http://doi.org/10.1002/1521-3951(200201)229:1<597::AID-PSSB597>3.0.CO;2-P
Abstract: Cyclotron resonance in CdTe/CdMgTe quantum wells (QWs) was studied. Due to the polaron effect the zero-field effective mass is strongly influenced by the QW width. The experimental data have been described theoretically by taking into account electron-phonon coupling and the nonparabolicity of the conduction band. The subband structure was calculated self-consistently. The best fit was obtained for an electron-phonon coupling constant alpha = 0.3 and bare electron mass of m(b) = 0.092m(0).
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.674
Times cited: 10
DOI: 10.1002/1521-3951(200201)229:1<597::AID-PSSB597>3.0.CO;2-P
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“Electron-electron interactions in bilayer graphene quantum dots”. Zarenia M, Partoens B, Chakraborty T, Peeters FM, Physical review : B : condensed matter and materials physics 88, 245432 (2013). http://doi.org/10.1103/PhysRevB.88.245432
Abstract: A parabolic quantum dot (QD) as realized by biasing nanostructured gates on bilayer graphene is investigated in the presence of electron-electron interaction. The energy spectrum and the phase diagram reveal unexpected transitions as a function of a magnetic field. For example, in contrast to semiconductor QDs, we find a valley transition rather than only the usual singlet-triplet transition in the ground state of the interacting system. The origin of these features can be traced to the valley degree of freedom in bilayer graphene. These transitions have important consequences for cyclotron resonance experiments.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.88.245432
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“Electron energy and temperature relaxation in graphene on a piezoelectric substrate”. Zhang SH, Xu W, Peeters FM, Badalyan SM, Physical review : B : condensed matter and materials physics 89, 195409 (2014). http://doi.org/10.1103/PhysRevB.89.195409
Abstract: We study the energy and temperature relaxation of electrons in graphene on a piezoelectric substrate. Scattering from the combined potential of extrinsic piezoelectric surface acoustical (PA) phonons of the substrate and intrinsic deformation acoustical phonons of graphene is considered for a (non) degenerate gas of Dirac fermions. It is shown that in the regime of low energies or temperatures the PA phonons dominate the relaxation and change qualitatively its character. This prediction is relevant for quantum metrology and electronic applications using graphene devices and suggests an experimental setup for probing electron-phonon coupling in graphene.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 18
DOI: 10.1103/PhysRevB.89.195409
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“Electron-energy-loss spectra of NiO”. Dobysheva LV, Potapov PL, Schryvers D, Physical review : B : condensed matter and materials physics 69, 184404 (2004). http://doi.org/10.1103/PhysRevB.69.184404
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PhysRevB.69.184404
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“Electron energy-loss spectroscopy and first-principles calculation studies on a Ni-Ti shape memory alloy”. Yang Z, Tirry W, Lamoen D, Kulkova S, Schryvers D, Acta materialia 56, 395 (2008). http://doi.org/10.1016/j.actamat.2007.10.001
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.301
Times cited: 20
DOI: 10.1016/j.actamat.2007.10.001
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“Electron energy-loss spectroscopy study of NiTi shape memory alloys”. Yang ZQ, Schryvers D, Materials science and engineering: part A: structural materials: properties, microstructure and processing 481, 214 (2008). http://doi.org/10.1016/j.msea.2006.12.227
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.094
Times cited: 7
DOI: 10.1016/j.msea.2006.12.227
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“Electron-hole symmetry and solutions of Richardson pairing model”. Pogosov WV, Lin N, Misko VR, European physical journal : B : condensed matter and complex systems 86, 235 (2013). http://doi.org/10.1140/epjb/e2013-40234-9
Abstract: Richardson approach provides an exact solution of the pairing Hamiltonian. This Hamiltonian is characterized by the electron-hole pairing symmetry, which is however hidden in Richardson equations. By analyzing this symmetry and using an additional conjecture, fulfilled in solvable limits, we suggest a simple expression of the ground state energy for an equally-spaced energy-level model, which is applicable along the whole crossover from the superconducting state to the pairing fluctuation regime. Solving Richardson equations numerically, we demonstrate a good accuracy of our expression.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 1.461
Times cited: 6
DOI: 10.1140/epjb/e2013-40234-9
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“Electron inelastic, scattering and anisotropy: the two-dimensional point of view”. Radtke G, Botton GA, Verbeeck J, Ultramicroscopy 106, 1082 (2006). http://doi.org/10.1016/j.ultramic.2006.04.023
Abstract: The measurement of the electronic structure of anisotropic materials using energy loss near edge structure (ELNES) spectroscopy is an important field of microanalysis in transmission electron microscopy. We present a novel method to study the angular dependence of electron inelastic scattering in anisotropic materials. This method has been applied to the study of 1s -> pi* and sigma* transitions on the carbon K edge in pyrolitic graphite. An excellent agreement between experimental and theoretical two-dimensional scattering patterns has been found. In particular, the need of a fully relativistic calculation of the inelastic scattering cross-section to explain the experimental results is demonstrated. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.843
Times cited: 5
DOI: 10.1016/j.ultramic.2006.04.023
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“Electron microscopic and X-ray structural analysis of the layered crystals TaReSe4: structure, defect structure, and microstructure, including rotation twins”. Volkov VV, van Landuyt J, Amelinckx S, Pervov VS, Makhonina EV, Journal of solid state chemistry 135, 235 (1998). http://doi.org/10.1006/jssc.1997.7621
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.299
Times cited: 3
DOI: 10.1006/jssc.1997.7621
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“An electron microscopic study of highly oriented undoped and FeCl3-doped poly (p-phenylenevinylene)”. Zhang XB, Van Tendeloo G, van Landuyt J, van Dyck D, Briers J, Bao Y, Geise HJ, Macromolecules 29, 1554 (1996). http://doi.org/10.1021/ma9513067
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
Impact Factor: 5.8
Times cited: 10
DOI: 10.1021/ma9513067
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