Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailElectric control of the magnetization in BiFeO3/LaFeO3 superlattices
Zanolli, Zeila ULiege; Wojdeł, Jacek; Iniguez, Jorge et al

in Physical Review B (2013), 88

First-principles techniques are used to investigate the behavior of BiFeO3/LaFeO3 perovskite oxide superlattices epitaxially grown on a (001)-SrTiO3 substrate. The calculations show that 1/1 superlattices ... [more ▼]

First-principles techniques are used to investigate the behavior of BiFeO3/LaFeO3 perovskite oxide superlattices epitaxially grown on a (001)-SrTiO3 substrate. The calculations show that 1/1 superlattices exhibit a Pmc21 ground state combining a trilinear coupling of one polar and two oxygen rotational lattice modes, and weak ferromagnetism. The microscopic mechanism allowing one to manipulate the magnetization with an electric field in such systems is presented and its dependence on strain and chemical substitution is discussed. BiFeO3/LaFeO3 artificial superlattices appear to be good candidates to achieve electric switching of magnetization at room temperature. [less ▲]

Detailed reference viewed: 36 (2 ULiège)
Full Text
See detailElectric current crowding effects in microstructured superconductors
Adami, Obaïd-Allah ULiege

Doctoral thesis (2016)

Many applications of modern electronic devices are based on thin film geometries including sharp turns, holes and exhibiting inhomogeneities. The inevitable detour of current streamlines around such ... [more ▼]

Many applications of modern electronic devices are based on thin film geometries including sharp turns, holes and exhibiting inhomogeneities. The inevitable detour of current streamlines around such obstacles cause an inhomogeneous current density profile giving rise to current crowding. The goal of my research is to highlight the current crowding effects in micro and nanopatterned superconducting films. [less ▲]

Detailed reference viewed: 79 (20 ULiège)
Full Text
See detailElectric current crowding in nanostructured conductors
Silhanek, Alejandro ULiege

Conference (2015, May 24)

When current stream lines are forced to depart from their rectilinear trajectory due to the presence of an obstacle, they conglomerate at the sharp bends encountered on their paths. The consequent current ... [more ▼]

When current stream lines are forced to depart from their rectilinear trajectory due to the presence of an obstacle, they conglomerate at the sharp bends encountered on their paths. The consequent current crowding is present in normal metals as well as in superconductors and has been, since long ago, identified as a key player in electromigration phenomena leading to failure in integrated circuit interconnects while might also be at the origin of local ablation in planar plasmonic structures. More recently, current crowding has been recognized as an important factor limiting the performance of superconducting single-photon detectors, leading to flux quanta motion rectification, or being a source of unwanted ratchet signal and depletion of surface barriers for magnetic flux penetration. In this talk, we will also show that in nanostructured superconductors at low temperatures, current crowding can trigger abrupt flux avalanches developing well defined geometrical patterns. Our experimental findings are backed up to the finest details, by simulations based on a phenomenological thermomagnetic model which, in turn, can be used to predict such complex structures and, given its reliability, allows one to estimate physical variables of more difficult experimental access, such as the local values of temperature and electric field. [less ▲]

Detailed reference viewed: 54 (13 ULiège)
Peer Reviewed
See detailAn electric current transducer for industrial use
Lewis, Christopher P.; Hesketh, Thomas G.; Kraft, Michaël ULiege

in Proceedings of the 5th International Conference on Optimization of Electric and Electronic Equipments (1996)

Detailed reference viewed: 3 (0 ULiège)
Peer Reviewed
See detailElectric Dipole Transitions in Atomic Oxygen and the lifetimes of the 2p3(4S°)3s5S° and 3S° States
Biémont, Emile ULiege; Zeippen, C. J.

in Astronomy and Astrophysics (1992), 265

Detailed reference viewed: 23 (4 ULiège)
Full Text
Peer Reviewed
See detailElectric Field Control of Jahn-Teller Distortions in Bulk Perovskites
Varignon, Julien ULiege; Bristowe, Nicholas ULiege; Ghosez, Philippe ULiege

in Physical Review Letters (2016), 116

The Jahn-Teller distortion, by its very nature, is often at the heart of the various electronic properties displayed by perovskites and related materials. Despite the Jahn-Teller mode being nonpolar, we ... [more ▼]

The Jahn-Teller distortion, by its very nature, is often at the heart of the various electronic properties displayed by perovskites and related materials. Despite the Jahn-Teller mode being nonpolar, we devise and demonstrate, in the present Letter, an electric field control of Jahn-Teller distortions in bulk perovskites. The electric field control is enabled through an anharmonic lattice mode coupling between the Jahn-Teller distortion and a polar mode. We confirm this coupling and quantify it through first-principles calculations. The coupling will always exist within the Pb21m space group, which is found to be the favored ground state for various perovskites under sufficient tensile epitaxial strain. Intriguingly, the calculations reveal that this mechanism is not only restricted to Jahn-Teller active systems, promising a general route to tune or induce novel electronic functionality in perovskites as a whole. [less ▲]

Detailed reference viewed: 23 (10 ULiège)
Full Text
Peer Reviewed
See detailElectric Power Network State Tracking from Multirate Measurements
Alcaide-Moreno, Boris; Fuerte-Esquivel, Claudio; Glavic, Mevludin et al

in IEEE Transactions on Instrumentation and Measurement (2018), 67

This paper proposes a novel tracking state estimator to process both fast-rate synchronized phasor and slow rate SCADA measurements. The former are assumed to be in limited number. The latter are ... [more ▼]

This paper proposes a novel tracking state estimator to process both fast-rate synchronized phasor and slow rate SCADA measurements. The former are assumed to be in limited number. The latter are exploited as and when they arrive to the control center. In order to restore observability, after each execution of the tracking state estimator, forecasted SCADA measurements are used as pseudo-measurements in the next estimation. An event detection analysis allows assessing if the system is in quasi steady-state. If so, an innovation analysis is performed to identify and eliminate erroneous SCADA measurements. The system state is computed by Hachtel’s augmented matrix method. The option of exploiting time-tagged SCADA measurements is also considered. The method is illustrated through detailed dynamic simulations of a test system evolving towards voltage collapse, with and without emergency control. [less ▲]

Detailed reference viewed: 75 (14 ULiège)
Full Text
Peer Reviewed
See detailElectrical activity of the bovine uterus prior to and post parturition.
Hanzen, Christian ULiege

in Veterinary Research Communications (1981), 5(2), 143-50

Recordings of electrical activity of six different areas of the uterus were obtained from two pregnant cows before and after delivery of their calves. Periods of activity occurred as spike bursts of ... [more ▼]

Recordings of electrical activity of six different areas of the uterus were obtained from two pregnant cows before and after delivery of their calves. Periods of activity occurred as spike bursts of potentials which occupied 52% of the recording time before delivery and 92% at the expulsive phase. The mean duration of the bursts was nearly doubled in the last ten hours prior to parturition without changes in their frequency. After delivery, the activity of the uterus occupied 29% of the recording time and consisted of long-lasting periods of spike bursts whose frequency was nearly halved. The alternation of periods of activity and quiescence represents the basic motility pattern of the pregnant uterus. Periods of quiescence are shortened at the time of expulsion and become predominant in the empty uterus, a phenomenon paralleled by changes in the temporal organisation of the number of spike bursts with the periods of activity. [less ▲]

Detailed reference viewed: 16 (5 ULiège)
Peer Reviewed
See detailElectrical Activity of Threading Dislocations and Defect Complexes in GeSn Epitaxial Layers
Gupta, Somya; Simoen, Eddy; Asano, Takanori et al

Conference (2013, June 04)

Detailed reference viewed: 136 (16 ULiège)
Full Text
Peer Reviewed
See detailElectrical and dielectric properties of carbon black filled co-continuous two-phase polymer blends
Calberg, Cédric ULiege; Blacher, Silvia ULiege; Gubbels, F. et al

in Journal of Physics D - Applied Physics (1999), 32(13), 1517-1525

The electrical and dielectric properties of co-continuous polystyrene (PS)/ρoly(methylmethacrylate)(PMMA) blends loaded with carbon black (CB) of a special grade (BP 1000) have been studied. They strongly ... [more ▼]

The electrical and dielectric properties of co-continuous polystyrene (PS)/ρoly(methylmethacrylate)(PMMA) blends loaded with carbon black (CB) of a special grade (BP 1000) have been studied. They strongly depend on the selective localization of the CB particles at the blend interface quite consistently with the double percolation concept. The interfacial localization of CB contributes to the stabilization of the phase morphology against thermal post treatment. Nevertheless, the sample annealing has a very favourable effect on the percolation threshold that decreases The composition range in which phases are co-continuous is also increased by the addition of the filler. Dispersion of the conductance and the dielectric constant has been measured in the wide frequency range 10-4-108 Hz for blends containing 0-5 wt% CB. On the basis of these results, the mechanism of electrical transport (trapping, hopping, tunnelling, percolation) has been discussed in relation to the CB loading and the optimum loading has been identified for the electrical and dielectric properties to be stable and reproducible [less ▲]

Detailed reference viewed: 21 (3 ULiège)
Full Text
Peer Reviewed
See detailElectrical and Magnetic Characterization of BSCCO and YBCO HTS Tapes for Fault Current Limiter Application
Lamas, Jerika S; Baldan, Carlos A; Shigue, Carlos Y et al

in IEEE Transactions on Applied Superconductivity (2011), 21(3), 3398-3402

Several high temperature superconductor (HTS) tapes have been developed since the late eighties. Due to the new techniques applied for their production, HTS tapes are becoming feasible and practical for ... [more ▼]

Several high temperature superconductor (HTS) tapes have been developed since the late eighties. Due to the new techniques applied for their production, HTS tapes are becoming feasible and practical for many applications. In this work, we present the test results of five commercial HTS tapes from the BSCCO and YBCO families (short samples of 200 mm). We have measured and analyzed their intrinsic and extrinsic properties and compared their behaviors for fault current limiter (FCL) applications. Electrical measurements were performed to determine the critical current and the n value through the V-I relationship under DC and AC magnetic fields. The resistance per unit length was determined as a function of temperature. The magnetic characteristics were analyzed through susceptibility curves as a function of temperature. As transport current generates a magnetic field surrounding the HTS material, the magnetic measurements indicate the magnetic field supported by the tapes under a peak current 1.5 times higher than the critical current, I(c). By pulsed current tests the recovery time and the energy/volume during a current fault were also analyzed. These results are in agreement with the data found in the literature giving the most appropriate performance conductor for a FCL device (I(peak) = 4 kA) to be used in a 220 V-60 Hz grid. [less ▲]

Detailed reference viewed: 27 (1 ULiège)
Full Text
Peer Reviewed
See detailElectrical and mechanical activity of the cervix in the ewe during pregnancy and parturition.
Toutain, P. L.; Garcia-Villar, R.; Hanzen, Christian ULiege et al

in Journal of Reproduction and Fertility (1983), 68

Detailed reference viewed: 18 (1 ULiège)
Peer Reviewed
See detailELECTRICAL AND THERMOMAGNETIC EFFECTS IN BI1.7PB0.3SR2CA2CU3O10 SUPERCONDUCTING CERAMICS
Pekala, M.; Bougrine, Hassan ULiege; Ausloos, Marcel ULiege

in Journal of Physics : Condensed Matter (1995), 7(28), 5607-5621

We report the electrical resistivity and thermoelectric power of polycrystalline Pb-doped Pi 2:2:2:3 superconductors. In particular the mixed-state properties are investigated by measuring the ... [more ▼]

We report the electrical resistivity and thermoelectric power of polycrystalline Pb-doped Pi 2:2:2:3 superconductors. In particular the mixed-state properties are investigated by measuring the longitudinal and transverse (Nernst) thermoelectric power. For the first time we show the presence of hysteresis in a high magnetic field for the Nernst effect. We discuss the variation with magnetic field in the properties with respect to the zero-field case and show the power-law behaviour with exponents depending on the transport quantity. We extract 'derived properties' such as the effective mass, the transport entropy, the Ginzburg-Landau parameter, the thermal Hall angle and the activation energy and compare them with previous data on related systems. [less ▲]

Detailed reference viewed: 23 (1 ULiège)
Full Text
Peer Reviewed
See detailElectrical characterization of InGaN/GaN multiple-quantum-well structures by thermal admittance spectroscopy
Nguyen, Ngoc Duy ULiege; Schmeits, Marcel; Germain, Marianne et al

in Physica Status Solidi C. Current Topics in Solid State Physics (2002)

Experimental results of electrical characterization of InGaN/GaN multiple-quantum-well electrolu- minescence test structures obtained by thermal admittance spectroscopy are presented. The stu- died GaN ... [more ▼]

Experimental results of electrical characterization of InGaN/GaN multiple-quantum-well electrolu- minescence test structures obtained by thermal admittance spectroscopy are presented. The stu- died GaN : Mg/5 × (InGaN/GaN)/GaN:Si structures were grown on c-plane sapphire substrate by metal-organic vapor phase epitaxy. Admittance measurements were conducted from room tem- perature down to 125 K for a wide frequency range and for different applied bias voltages. Analy- sis of the capacitance versus frequency curves shows the presence of several cutoff frequencies which originate from the response of equivalent RC series circuits and give peaks in the conduc- tance divided by angular frequency. The dependence of the position and the amplitude of these peaks on temperature is discussed. [less ▲]

Detailed reference viewed: 38 (4 ULiège)
Peer Reviewed
See detailElectrical characterization of InGaN/GaN multiple-quantum-well structures by thermal admittance spectroscopy
Nguyen, Ngoc Duy ULiege; Schmeits, Marcel; Germain, Marianne et al

Poster (2002)

Detailed reference viewed: 26 (0 ULiège)