“Microscopic theory of orientational disorder and lattice instability in solid C70”. Callebaut AK, Michel KH, Physical review : B : condensed matter and materials physics 52, 15279 (1995). http://doi.org/10.1103/PhysRevB.52.15279
Abstract: We have developed a microscopic theory which describes the orientational dynamics of C-70 molecules and its coupling to lattice displacements in the face-centered-cubic phase of C-70 fullerite. The single-molecule orientational density distribution in the disordered phase is calculated. The ferroelastic transition to the rhombohedral phase is investigated. The discontinuity of the orientational order parameter at the phase transition is calculated. It is found that the transition leads to a stretching of the primitive unit cell along a [111] cubic direction. A softening of the elastic constant c(44) at the transition is predicted.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 20
DOI: 10.1103/PhysRevB.52.15279
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“Impurity band and magnetic-field-induced metal-insulator transition in a doped GaAs/AlxGa1-xAs superlattice”. Hilber W, Helm M, Peeters FM, Alavi K, Pathak RN, Physical review : B : condensed matter and materials physics 53, 6919 (1996). http://doi.org/10.1103/PhysRevB.53.6919
Abstract: A combination of infrared spectroscopy and magnetotransport is used to investigate the impurity band and the magnetic-field-induced metal-insulator transition in n-type GaAs/AlxGa1-xAs superlattices. The dropping of the Fermi level from the conduction band into the impurity band upon increasing magnetic field is observed in a sample doped to n=4n(c), where n(c) is the critical density according to the Mott criterion. The metal-insulator transition takes place while the Fermi level is in the impurity band, with no qualitative change from the metallic to the insulating side. Due to the anisotropy of the superlattice band structure, the metal-insulator transition is shifted to higher magnetic field, when the magnetic field is tilted away from the growth axis towards the layer planes.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 14
DOI: 10.1103/PhysRevB.53.6919
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“Microscopic theory of the rhombohedral phase and transition to the monoclinic phase of solid C70”. Nikolaev AV, Michel KH, Physical review : B : condensed matter and materials physics 54, 12733 (1996). http://doi.org/10.1103/PhysRevB.54.12733
Abstract: Starting from a model of microscopic interactions between C-70 molecules, we have developed a theory which describes the orientational dynamics and its coupling to lattice displacements in the rhombohedral phase of C-70 fullerite. The Landau free energy is calculated. We obtain a first-order phase transition to a monoclinic structure with the space group P2(1)/m. The transition is driven by the condensation of orientational quadrupoles at the F point of the Brillouin zone of the rhombohedral lattice. We find no evidence that the monoclinic structure is connected with the freezing in of orientations around the fivefold molecular axis. We calculate the lattice strains that are associated with the transition to the monoclinic structure. The theory is compared with a range of experimental data on the phase transition.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 5
DOI: 10.1103/PhysRevB.54.12733
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“Real-space characterization of short-range order in Cu-Pd alloys”. Rodewald M, Rodewald K, De Meulenaere P, Van Tendeloo G, Physical review : B : condensed matter and materials physics 55, 14173 (1997). http://doi.org/10.1103/PhysRevB.55.14173
Abstract: Cu-Pd alloys containing 10, 20, 30, 40, and 50 at. % Pd and quenched from a temperature just above the ordering temperature T-c are investigated by electron diffraction and high-resolution electron microscopy (HREM). The results show diffuse electron diffraction intensities at {100} and {110} positions for the alloy with 10 at. % Pd, but with a characteristic twofold and fourfold splitting for the alloys with more than 10 at. % Pd. High-resolution images show the formation of microdomains best developed between 20 and 30 at. % Pd. A real-space characterization has been performed by applying videographic real-structure simulations revealing that the splitting of the diffuse maxima depends on the average distance between microdomains of Cu3Au type in antiphase with each other. By applying image processing routines on the HREM images, correlation vectors are identified which correspond to correlations between microdomains.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 15
DOI: 10.1103/PhysRevB.55.14173
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“Anisotropic cluster model for the short-range order in Cu1-xPdx-type alloys”. De Meulenaere P, Rodewald M, Van Tendeloo G, Physical review : B : condensed matter and materials physics 57, 11132 (1998). http://doi.org/10.1103/PhysRevB.57.11132
Abstract: The split diffuse maxima around the {110} and {100} positions in the diffraction pattern of short-range-ordered Cu1-xPdx alloys (x=0.10...0.60) are attributed to small atomic clusters, being part of the underlying fee lattice. By analyzing the reciprocal space geometry, our cluster method identifies two prominent cluster types: the tetrahedron of nearest neighbors and a linear three-points cluster along the [110] directions. Since both cluster types contain different information on the same nearest-neighbor correlations, local anisotropy has to be assumed. It is shown that the three interatomic pair interactions within these basic clusters are sufficient to generate the spot splitting in the diffraction pattern. A ground-state analysis with these interactions reproduces the results of the anisotropic next-nearest-neighbor Ising model.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 1
DOI: 10.1103/PhysRevB.57.11132
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“Size mismatch : a crucial factor for generating a spin-glass insulator in manganites”. Maignan A, Martin C, Van Tendeloo G, Hervieu M, Raveau B, Physical review : B : condensed matter and materials physics 60, 15214 (1999). http://doi.org/10.1103/PhysRevB.60.15214
Abstract: Thr structural, electronic, and magnetic properties of the highly mismatched perovskite oxides, Th(0.35)A(0.65)MnO(3), where Ais for the alkaline earth divalent cations (Ca, Ba, Sr), which are all characterized by the same large tolerance factor (t=0.934), have been investigated by using electron microscopy, electrical resistivity, magnetic susceptibility, and magnetization. It is clearly established that a transition from ferromagnetic metallic towards spin-glass insulator samples is induced as the A-site cationic size mismatch is increased. Moreover, the magnetoresistance (MR) properties of these manganites are strongly reduced for the spin-glass insulators, demonstrating that the A-sire cationic disorder is detrimental for the colossal MR properties. Based on these results, a new electronic and magnetic diagram is established that shows that the A-site disorder, rather than the A-site average cationic size (or t) is the relevant factor for generating spin-glass insulating manganites. [S0163-1829(99)01746-4].
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 75
DOI: 10.1103/PhysRevB.60.15214
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“In situ HREM irradiation study of point-defect clustering in MBE-grown strained Si1-xGex/(001)Si structures”. Fedina L, Lebedev OI, Van Tendeloo G, van Landuyt J, Mironov OA, Parker EHC, Physical review : B : condensed matter and materials physics 61, 10336 (2000). http://doi.org/10.1103/PhysRevB.61.10336
Abstract: We present a detailed analysis of the point-defect clustering in strained Si/Si(1-x)Ge(x)/(001)Si structures, including the interaction of the point defects with the strained interfaces and the sample surface during 400 kV electron irradiation at room temperature. Point-defect cluster formation is very sensitive to the type and magnitude of the strain in the Si and Si(1-x)Ge(x) layers. A small compressive strain (-0.3%) in the SiGe alloy causes an aggregation of vacancies in the form of metastable [110]-oriented chains. They are located on {113} planes and further recombine with interstitials. Tensile strain in the Si layer causes an aggregation of interstitial atoms in the forms of additional [110] rows which are inserted on {113} planes with [001]-split configurations. The chainlike configurations are characterized by a large outward lattice relaxation for interstitial rows (0.13 +/-0.01 nm) and a very small inward relaxation for vacancy chains (0.02+/-0.01 nm). A compressive strain higher than -0.5% strongly decreases point-defect generation inside the strained SiGe alloy due to the large positive value of the formation volume of a Frenkel pair. This leads to the suppression of point-defect clustering in a strained SiGe alloy so that SiGe relaxes via a diffusion of vacancies from the Si layer, giving rise to an intermixing at the Si/SiGe interface. In material with a 0.9% misfit a strongly increased flow of vacancies from the Si layer to the SiGe layer and an increased biaxial strain in SiGe bath promote the preferential aggregation of vacancies in the (001) plane, which relaxes to form intrinsic 60 degrees dislocation loops.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 27
DOI: 10.1103/PhysRevB.61.10336
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“Vortex states in superconducting rings”. Baelus BJ, Peeters FM, Schweigert VA, Physical review : B : condensed matter and materials physics 61, 9734 (2000). http://doi.org/10.1103/PhysRevB.61.9734
Abstract: The superconducting state. of a thin superconducting disk with a hole is studied within the, nonlinear Ginzburg-Landau theory in which the demagnetization effect is accurately taken into account. We find that the flux through the hole is not quantized, the superconducting state is stabilized with increasing size of the hole for fixed radius of the disk, and a transition to a multivortex state is found if the disk is sufficiently large. Breaking the circular symmetry through a non-central-location of the hole in the disk favors the multivortex state.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 78
DOI: 10.1103/PhysRevB.61.9734
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“Bright to dark exciton transition in symmetric coupled quantum wells”. Chang K, Peeters FM, Physical review : B : condensed matter and materials physics 63 (2001). http://doi.org/10.1103/PhysRevB.63.153307
Abstract: The energy dispersion of an exciton in a coupled quantum well is modified by an external in-plane magnetic field. We find that the in-plane magnetic field can shift the ground state of the magnetoexciton from a zero in-plane center-of-mass (CM) momentum to a finite CM momentum, and render the ground state of the magnetoexciton stable against radiative recombination due to momentum conservation. At the same time, a spatial separation of the electron and hole is realized. Thus an in-plane magnetic field can be used to tailor the radiative properties of excitons in coupled quantum wells.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 42
DOI: 10.1103/PhysRevB.63.153307
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“Evidence for another low-temperature phase transition in tetragonal Pb(ZrxTi1-x)O3 (x=0.515,0.520)”. Mishra RSK, Pandey D, Lemmens H, Van Tendeloo G, Physical review : B : condensed matter and materials physics 64, 054104 (2001). http://doi.org/10.1103/PhysRevB.64.054101
Abstract: Results of dielectric and resonance frequency (f(r)) measurements below room temperature are presented for Pb(ZrxTi1-x)O-3, x = 0.515 and 0.520. It is shown that the temperature coefficient of f(r) changes sign from negative to positive around 210 and 265 K for x = 0.520 and 200 and 260 K for x = 0.515. Anomalies in the real part of the dielectric constant (epsilon') are observed around the same temperatures at which the temperature coefficient of f(r) changes sign because of the electrostrictive coupling between the elastic and dielectric responses. Low-temperature powder x-ray-diffraction (XRD) data, however, reveal only one transition from the tetragonal to monoclinic phase similar to that reported by Noheda et al. [Phys. Rev. B, 61, 8687 (2000)]. Electron-diffraction data, on the other hand, reveal yet another structural transition at lower temperatures corresponding to the second anomaly in the epsilon' vs T and f(r) vs T curves. This second transition is shown to be a cell-doubling transition not observed by Noheda et al. in their XRD studies. The observation of superlattice reflections raises doubts about the correctness of the Cm space group proposed by Noheda et al. for the monoclinic phase of Pb(ZrxTi(1-x))O-3 below the second transition temperature.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
DOI: 10.1103/PhysRevB.64.054101
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“Superconducting properties of mesoscopic cylinders with enhanced surface superconductivity”. Baelus BJ, Yampolskii SV, Peeters FM, Montevecchi E, Indekeu JO, Physical review : B : condensed matter and materials physics 65, 024510 (2002). http://doi.org/10.1103/PhysRevB.65.024510
Abstract: The superconducting state of an infinitely long superconducting cylinder surrounded by a medium which enhances its superconductivity near the boundary is studied within the nonlinear Ginzburg-Landau theory. This enhancement can be due to the proximity of another superconductor or due to surface treatment. Quantities such as the free energy, the magnetization and the Cooper-pair density are calculated. Phase diagrams are obtained to investigate how the critical field and the critical temperature depend on this surface enhancement for different values of the Ginzburg-Landau parameter kappa. Increasing the superconductivity near the surface leads to higher critical fields and critical temperatures. For small cylinder diameters only giant vortex states nucleate, while for larger cylinders multivortices can nucleate. The stability of these multivortex states also depends on the surface enhancement. For type-I superconductors we found the remarkable result that for a range of values of the surface extrapolation length the superconductor can transit from the Meissner state into superconducting states with vorticity L > 1. Such a behavior is not found for the case of large kappa, i.e., type-II superconductivity,
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 13
DOI: 10.1103/PhysRevB.65.024510
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“Phase transition and magnetic anisotropy of (La,Sr)MnO3 thin films”. Wang Z-H, Kronmüller H, Lebedev OI, Gross GM, Razavi FS, Habermeier HU, Shen BG, Physical review : B : condensed matter and materials physics 65, 054411 (2002). http://doi.org/10.1103/PhysRevB.65.054411
Abstract: The magnetic proper-ties and their correlation with the microstructure and electrical transport are investigated in La0.88Sr0.1MnO3 films grown on (100)SrTiO3 Single crystal substrates with thickness ranging from 100 to 2500 Angstrom. The ultrathin film (t = 100 Angstrom) has a single ferromagnetic transition (FMT) at T-c of 250 K, whereas the thicker films exhibit two FMTs, with the main one at a lowered T-c of 200 K while the minor one around 300 K. Furthermore, a thickness dependent magnetic anisotropy has been found, strongly indicating the existence of strain effect, which is also revealed by the transmission electron microscopy study. The suppressed Jahn-Teller distortion (JTD) by the epitaxial strain, and the recovered JTD due to the strain relexation are suggested to explain the metallic behavior in thin films and the insulating behavior in the thick film (t = 2500 Angstrom), repectively.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 23
DOI: 10.1103/PhysRevB.65.054411
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“Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides”. Wang XF, Vasilopoulos P, Peeters FM, Physical review : B : condensed matter and materials physics 65, 165217 (2002). http://doi.org/10.1103/PhysRevB.65.165217
Abstract: Ballistic spin transport through waveguides, with symmetric or asymmetric double stubs attached to them periodically, is studied systematically in the presence of a weak spin-orbit coupling that makes the electrons precess. By an appropriate choice of the waveguide length and of the stub parameters injected spin-polarized electrons can be blocked completely and the transmission shows a periodic and nearly-square-type behavior, with values 1 and 0, with wide gaps when only one mode is allowed to propagate in the waveguide. A similar behavior is possible for a certain range of the stub parameters even when two modes can propagate in the waveguide and the conductance is doubled. Such a structure is a good candidate for establishing a realistic spin transistor. A further modulation of the spin current can be achieved by inserting defects in a finite-number stub superlattice. Finite-temperature effects on the spin conductance are also considered.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 112
DOI: 10.1103/PhysRevB.65.165217
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“Effect of isotropic versus anisotropic elasticity on the electronic structure of cylindrical InP/In0.49Ga0.51P self-assembled quantum dots”. Tadić, M, Peeters FM, Janssens KL, Physical review : B : condensed matter and materials physics 65, 165333 (2002). http://doi.org/10.1103/PhysRevB.65.165333
Abstract: The electronic structure of disk-shaped InP/InGaP self-assembled quantum dots is calculated within the effective-mass theory. The strain-dependent 6x6 multiband Hamiltonian for the valence band is simplified into an axially symmetric form. Both the continuum mechanical model, discretized by finite elements, and the isotropic model are used to calculate the strain distribution and their results are critically compared. The dependence of the electron and the hole energy levels on the dimensions of the quantum dot is investigated. We found that both the electron and hole energies are underestimated if the strain distribution is calculated by the isotropic elasticity theory. The agreement between the electron energies for the two approaches is better for thinner quantum dots. The heavy holes are confined inside the quantum dot, while the light holes are located outside the disk, but confined by the strain field near the edge of the disk periphery. We found that the (h) over bar /2 hole ground state crosses the 3 (h) over bar /2 ground state when the height of the quantum dot increases and becomes the ground state for sufficiently thick quantum disks. The higher hole levels exhibit both crossings between the states of the different parity and anticrossings between the states of the same parity.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 72
DOI: 10.1103/PhysRevB.65.165333
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“Correlated few-particle states in artificial bipolar molecule”. Anisimovas E, Peeters FM, Physical review : B : condensed matter and materials physics 65, 233302 (2002). http://doi.org/10.1103/PhysRevB.65.233302
Abstract: We investigate the ground and excited states of a bipolar artificial molecule composed of two vertically coupled quantum dots containing different type of carriers-electrons and holes-in equilibrium. The approach based on exact diagonalization is used and reveals an intricate pattern of ground-state angular momentum switching and a rearrangement of approximate single-particle levels as a function of the interdot coupling strength.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 14
DOI: 10.1103/PhysRevB.65.233302
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“Scattering of ballistic electrons at a mesoscopic spot of strong magnetic field”. Novoselov KS, Geim AK, Dubonos SV, Cornelissens YG, Peeters FM, Maan JC, Physical review : B : condensed matter and materials physics 65, 233312 (2002). http://doi.org/10.1103/PhysRevB.65.233312
Abstract: We report quenching of the Hall effect with increasing magnetic field confined in a micron-sized spot. Such fields were created by placing tall ferromagnetic pillars on top of a two-dimensional electron gas, which allowed us to achieve the field strength up to 0.4 T under the pillars in the absence of external field. The quenching is accompanied by an anomalous increase in resistance and occurs when the cyclotron diameter matches the size of the magnetic spot. The results are explained by a rapid increase in the number of electrons that are scattered or quasilocalized by the magnetic region.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.65.233312
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“Coupled mesoscopic superconductors : Ginzburg-Landau theory”. Baelus BJ, Yampolskii SV, Peeters FM, Physical review : B : condensed matter and materials physics 66, 024517 (2002). http://doi.org/10.1103/PhysRevB.66.024517
Abstract: The magnetic coupling between two concentric mesoscopic superconductors with nonzero thickness is studied using the nonlinear Ginzburg-Landau theory. We calculated the free energy, the expelled field, the total field profile, the Cooper-pair density, and the current density distribution. By putting a smaller superconducting disk or ring in the center of a larger ring, the properties change drastically. Extra ground-state transitions are found, where the total vorticity stays the same, but the vorticity of the inner superconductor changes by 1. Due to the magnetic coupling, the current in the external ring exhibits extra jumps at the transition fields where the vorticity of the inner superconductor changes. In this case, for certain temperatures, re-entrant behavior and switching on and off of the superconducting behavior of the rings are found as a function of the magnetic field. A H-T phase diagram is obtained for the situation where the inner ring has a higher critical temperature than the outer ring. An analytic expression for the magnetic coupling is obtained for thin rings and extreme type-II superconductors.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 11
DOI: 10.1103/PhysRevB.66.024517
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“Even-odd transition in the Shubnikov-de Haas oscillations in a two-dimensional electron gas subjected to periodic magnetic and electric modulations”. Shi J, Peeters FM, Edmonds KW, Gallagher BL, Physical review : B : condensed matter and materials physics 66, 035328 (2002). http://doi.org/10.1103/PhysRevB.66.035328
Abstract: We investigate low-temperature magnetotransport of high-mobility two-dimensional electron gases subjected to one-dimensional periodic magnetic and electric modulations. Our previous quantum perturbation theory is extended to lower temperatures and the energy broadening due to impurity scattering is incorporated. Numerical calculations are made for situations where several Landau bands overlap. We find that the Shubnikov-de Haas (SdH) oscillations are dominated by collisional resistance. The amplitudes of the SdH oscillations are strongly modulated and the positions of the SdH minima switch between even and odd Landau-level filling factors, in the resistance both parallel and perpendicular to the one-dimensional modulation. This is a consequence of the internal structure (i.e., smeared out van Hove singularities) of overlapping Landau bands. Our theoretical results are in good agreement with recent experiments.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 32
DOI: 10.1103/PhysRevB.66.035328
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“Stationary-phase slip state in quasi-one-dimensional rings”. Vodolazov DY, Baelus BJ, Peeters FM, Physical review : B : condensed matter and materials physics 66, 054531 (2002). http://doi.org/10.1103/PhysRevB.66.054531
Abstract: The nonuniform superconducting state in a ring in which the order parameter vanishing at one point is studied. This state is characterized by a jump of the phase by pi at the point where the order parameter becomes zero. In uniform rings such a state is a saddle-point state and consequently unstable. However, for nonuniform rings with, e.g., variations of geometrical or physical parameters or with attached wires this state can be stabilized and may be realized experimentally.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.66.054531
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“Dynamic transitions between metastable states in a superconducting ring”. Vodolazov DI, Peeters FM, Physical review : B : condensed matter and materials physics 66, 054537 (2002). http://doi.org/10.1103/PhysRevB.66.054537
Abstract: Applying the time-dependent Ginzburg-Landau equations, transitions between metastable states of a superconducting ring are investigated in the presence of an external magnetic field. It is shown that if the ring exhibits several metastable states at a particular magnetic field, the transition from one metastable state to another one is governed by both the relaxation time of the absolute value of the order parameter tau(\psi\) and the relaxation time of the phase of the order parameter tau(phi). We found that the larger the ratio tau(\psi\)/tau(phi), the closer the final state will be to the absolute minimum of the free energy, i.e., the thermodynamic equilibrium. The transition to the final state occurs through a subsequent set of single phase slips at a particular point along the ring.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 34
DOI: 10.1103/PhysRevB.66.054537
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“Dynamic response of artificial bipolar molecules”. Anisimovas E, Peeters FM, Physical review : B : condensed matter and materials physics 66, 075311 (2002). http://doi.org/10.1103/PhysRevB.66.075311
Abstract: We calculate the equilibrium properties and the dynamic response of two vertically coupled circular quantum dots populated by particles of different electrical charge sign, i.e., electrons and holes. The equilibrium density profiles are obtained and used to compute the frequencies and oscillator strengths of magnetoplasma excitations. We find a strong coupling between the modes derived from the center-of-mass modes of the individual dots which leads to an anticrossing with a pronounced oscillator strength transfer from the “acoustic” to the “optical” branch. Also, due to the breaking of the generalized Kohn theorem a number of other than center-of-mass modes are excited whose oscillator strengths, however, are rather weak.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 9
DOI: 10.1103/PhysRevB.66.075311
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“Theoretical model for the structural phase transition at the metal-insulator transition in polymerized KC60”. Verberck B, Nikolaev AV, Michel KH, Physical Review B 66, 165425 (2002). http://doi.org/10.1103/PhysRevB.66.165425
Abstract: The recently discovered structural transition in polymerized KC60 at about 50 K results in a doubling of the unit cell volume and accompanies the metal-insulator transition. Here we show that the ((a) over right arrow+(c) over right arrow,(b) over right arrow,(a) over right arrow-(c) over right arrow) superstructure results from small orientational charge density waves along the polymer chains and concomitant displacements of the surrounding K+ ions. The effect is specific for the space group Pmnn of KC60 and is absent in RbC60 and CsC60 (space group I2/m). The mechanism is relevant for the metal-insulator transition.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 10
DOI: 10.1103/PhysRevB.66.165425
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“SrTiO3(100)/(LaMnO3)m(SrMnO3)n layered heterostructures: a combined EELS and TEM study”. Verbeeck J, Lebedev OI, Van Tendeloo G, Mercey B, Physical review : B : condensed matter and materials physics 66, 184426 (2002). http://doi.org/10.1103/PhysRevB.66.184426
Abstract: Epitaxially grown heterostructures consisting of alternating layers of LaMnO(3) (LMO, 9 or 15 unit cells) and SrMnO(3) (SMO, 4 or 6 unit cells) on a SrTiO(3)(100) (STO(100)) substrate have been studied by a combination of high resolution transmission electron microscopy (HRTEM), electron diffraction, quantitative electron energy loss spectroscopy (EELS) with model fitting, energy filtered TEM (EFTEM) and imaging spectroscopy on an atomic scale. The combination of these techniques is necessary for the structural, chemical, and electronic characterization of these heterostructures. A model is proposed containing chemically and structurally sharp interfaces. The SrMnO(3) layers are stabilized in a Pm3m structure between two LMO layers. Tensile stress causes oxygen deficiency in the SMO layers increasing the number of 3d electrons on the Mn sites to resemble the Mn(3+) sites in LMO. The energy loss near edge structure (ELNES) of O and Mn is compared for both LMO and SMO layers and shows that the Mn-O bonds have a partially covalent character. The absence of a strong valency effect in the Mn ELNES is due to the oxygen vacancies in SMO.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 32
DOI: 10.1103/PhysRevB.66.184426
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“Multiple flux jumps and irreversible behavior of thin Al superconducting rings”. Vodolazov DY, Peeters FM, Dubonos SV, Geim AK, Physical review : B : condensed matter and materials physics 67, 054506 (2003). http://doi.org/10.1103/PhysRevB.67.054506
Abstract: An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic-field region the change of vorticity with magnetic field can be larger than unity. This behavior is connected with the existence of several metastable states of different vorticities. The intentional introduction of a defect in the ring has a large effect on the size of the flux jumps. Calculations based on the time-dependent Ginzburg-Landau model allows us to explain the experimental results semiquantitatively.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 49
DOI: 10.1103/PhysRevB.67.054506
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“Symmetry lowering at the structural phase transitions in NpO2 and UO2”. Nikolaev AV, Michel KH, Physical review : B : condensed matter and materials physics 68, 054112 (2003). http://doi.org/10.1103/PhysRevB.68.054112
Abstract: 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.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 15
DOI: 10.1103/PhysRevB.68.054112
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“Interaction between a superconducting vortex and an out-of-plane magnetized ferromagnetic disk: influence of the magnet geometry”. Milošević, MV, Peeters FM, Physical review : B : condensed matter and materials physics 68, 094510 (2003). http://doi.org/10.1103/PhysRevB.68.094510
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 55
DOI: 10.1103/PhysRevB.68.094510
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“Excitonic trions in vertically coupled quantum dots”. Anisimovas E, Peeters FM, Physical review : B : condensed matter and materials physics 68, 115310 (2003). http://doi.org/10.1103/PhysRevB.68.115310
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 19
DOI: 10.1103/PhysRevB.68.115310
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“Intersubband plasmons in quasi-one-dimensional electron systems on a liquid helium surface”. Tavares MRS, Hai G-Q, Peeters FM, Studart N, Physical review : B : condensed matter and materials physics 68, 140504 (2003). http://doi.org/10.1103/PhysRevB.68.140504
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.68.140504
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“Stability and transition between vortex configurations in square mesoscopic samples with antidots”. Berdiyorov GR, Baelus BJ, Milošević, MV, Peeters FM, Physical review : B : condensed matter and materials physics 68, 174521 (2003). http://doi.org/10.1103/PhysRevB.68.174521
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 51
DOI: 10.1103/PhysRevB.68.174521
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“Four-electron quantum dot in a magnetic field”. Tavernier MB, Anisimovas E, Peeters FM, Szafran B, Adamowski J, Bednarek S, Physical review : B : condensed matter and materials physics 68, 205305 (2003). http://doi.org/10.1103/PhysRevB.68.205305
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 87
DOI: 10.1103/PhysRevB.68.205305
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