Records |
Author |
Souza, J.C.B.; Vizarim, N.P.; Reichhardt, C.J.O.; Reichhardt, C.; Venegas, P.A. |
Title |
Magnus induced diode effect for skyrmions in channels with periodic potentials |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
35 |
Issue |
1 |
Pages |
015804-15810 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. The preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000880827900001 |
Publication Date |
2022-10-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
Call Number |
UA @ admin @ c:irua:192031 |
Serial |
7320 |
Permanent link to this record |
|
|
|
Author |
Menezes, R.M.; Sardella, E.; Cabral, L.R.E.; de Souza Silva, C.C. |
Title |
Self-assembled vortex crystals induced by inhomogeneous magnetic textures |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
31 |
Issue |
17 |
Pages |
175402 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We investigate the self-assembly of vortices in a type-II superconducting disk subjected to highly nonuniform confining potentials produced by inhomogeneous magnetic textures. Using a series of numerical experiments performed within the Ginzburg–Landau theory, we show that vortices can arrange spontaneously in highly nonuniform, defect-free crystals, reminiscent of conformal lattices, even though the strict conditions for the conformal crystal are not fulfilled. These results contradict continuum-limit theory, which predicts that the order of a nonuniform crystal is unavoidably frustrated by the presence of topological defects. By testing different cooling routes of the superconductor, we observed several different self-assembled configurations, each of which corresponding to one in a set of allowed conformal transformations, which depends on the magnetic and thermal histories of the system. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2019-01-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
|
Times cited |
|
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:191094 |
Serial |
8511 |
Permanent link to this record |
|
|
|
Author |
da Costa, D.R.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
Title |
Valley filtering in graphene due to substrate-induced mass potential |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
29 |
Issue |
21 |
Pages |
215502 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
The interaction of monolayer graphene with specific substrates may break its sublattice symmetry and results in unidirectional chiral states with opposite group velocities in the different Dirac cones (Zarenia et al 2012 Phys. Rev. B 86 085451). Taking advantage of this feature, we propose a valley filter based on a transversal mass kink for low energy electrons in graphene, which is obtained by assuming a defect region in the substrate that provides a change in the sign of the substrate-induced mass and thus creates a non-biased channel, perpendicular to the kink, for electron motion. By solving the time-dependent Schrodinger equation for the tight-binding Hamiltonian, we investigate the time evolution of a Gaussian wave packet propagating through such a system and obtain the transport properties of this graphene-based substrate-induced quantum point contact. Our results demonstrate that efficient valley filtering can be obtained, provided: (i) the electron energy is sufficiently low, i.e. with electrons belonging mostly to the lowest sub-band of the channel, and (ii) the channel length (width) is sufficiently long (narrow). Moreover, even though the transmission probabilities for each valley are significantly affected by impurities and defects in the channel region, the valley polarization in this system is shown to be robust against their presence. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000400092700002 |
Publication Date |
2017-04-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
15 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:152636 |
Serial |
8730 |
Permanent link to this record |
|
|
|
Author |
Leenaerts, O.; Partoens, B.; Peeters, F.M.; Volodin, A.; van Haesendonck, C. |
Title |
The work function of few-layer graphene |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
29 |
Issue |
3 |
Pages |
035003 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
A theoretical and experimental study of the work function of few-layer graphene is reported. The influence of the number of layers on the work function is investigated in the presence of a substrate, a molecular dipole layer, and combinations of the two. The work function of few-layer graphene is almost independent of the number of layers with only a difference between monolayer and multilayer graphene of about 60 meV. In the presence of a charge-donating substrate the charge distribution is found to decay exponentially away from the substrate and this is directly reflected in the work function of few-layer graphene. A dipole layer changes the work function only when placed in between the substrate and few-layer graphene through a change of the charge transfer between the two. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000425250600002 |
Publication Date |
2016-11-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
|
Times cited |
61 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ admin @ c:irua:164938 |
Serial |
8760 |
Permanent link to this record |
|
|
|
Author |
Bekaert, J.; Bringmans, L.; Milošević, M.V. |
Title |
Ginzburg-Landau surface energy of multiband superconductors : derivation and application to selected systems |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
35 |
Issue |
32 |
Pages |
325602-325610 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We determine the energy of an interface between a multiband superconducting and a normal half-space, in presence of an applied magnetic field, based on a multiband Ginzburg-Landau (GL) approach. We obtain that the multiband surface energy is fully determined by the critical temperature, electronic densities of states, and superconducting gap functions associated with the different band condensates. This furthermore yields an expression for the thermodynamic critical magnetic field, in presence of an arbitrary number of contributing bands. Subsequently, we investigate the sign of the surface energy as a function of material parameters, through numerical solution of the GL equations. Here, we consider two distinct cases: (i) standard multiband superconductors with attractive interactions, and (ii) a three-band superconductor with a chiral ground state with phase frustration, arising from repulsive interband interactions. Furthermore, we apply this approach to several prime examples of multiband superconductors, such as metallic hydrogen and MgB2, based on microscopic parameters obtained from first-principles calculations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000986281900001 |
Publication Date |
2023-05-03 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
Call Number |
UA @ admin @ c:irua:196664 |
Serial |
8875 |
Permanent link to this record |
|
|
|
Author |
Wang, S.; Tian, H.; Sun, M. |
Title |
Valley-polarized and enhanced transmission in graphene with a smooth strain profile |
Type |
A1 Journal article |
Year |
2023 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
|
Volume |
35 |
Issue |
30 |
Pages |
304002-304013 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
Abstract |
We explore the influence of strain on the valley-polarized transmission of graphene by employing the wave-function matching and the non-equilibrium Green's function technique. When the transmission is along the armchair direction, we show that the valley polarization and transmission can be improved by increasing the width of the strained region and increasing (decreasing) the extensional strain in the armchair (zigzag) direction. It is noted that the shear strain does not affect transmission and valley polarization. Furthermore, when we consider the smooth strain barrier, the valley-polarized transmission can be enhanced by increasing the smoothness of the strain barrier. We hope that our finding can shed new light on constructing graphene-based valleytronic and quantum computing devices by solely employing strain. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000977124700001 |
Publication Date |
2023-04-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.7 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 2.7; 2023 IF: 2.649 |
Call Number |
UA @ admin @ c:irua:196718 |
Serial |
8953 |
Permanent link to this record |
|
|
|
Author |
Reijniers, J.; Peeters, F.M. |
Title |
Snake orbits and related magnetic edge states |
Type |
A1 Journal article |
Year |
2000 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
12 |
Issue |
|
Pages |
9771-9786 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Engineering Management (ENM) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000165795500009 |
Publication Date |
2002-08-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
66 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2000 IF: 1.608 |
Call Number |
UA @ lucian @ c:irua:34352 |
Serial |
3045 |
Permanent link to this record |
|
|
|
Author |
Xu, W.; Peeters, F.M.; Devreese, J.T. |
Title |
Normal and hot electro-phonon resonance effect in a quasi-two-dimensional semiconductor system |
Type |
A1 Journal article |
Year |
1993 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
5 |
Issue |
15 |
Pages |
2307-2320 |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
Abstract |
The electro-phonon resonance effect is a consequence of a resonant interaction between two electric subbands mediated by an optical phonon. It occurs in a quasi-two-dimensional electron system each time the energy difference between two electric subbands equals the energy of a Lo phonon. We study the influence of this effect on the electron mobility by using the momentum balance equation. The temperature and electron density dependences of the resonances are studied in the linear and non-linear response regimes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
A1993KX70100004 |
Publication Date |
2002-08-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.346 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:102984 |
Serial |
2367 |
Permanent link to this record |
|
|
|
Author |
Titantah, J.T.; Lamoen, D. |
Title |
The effect of temperature on the structural, electronic and optical properties of sp3-rich amorphous carbon |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
20 |
Issue |
3 |
Pages |
035216,1-6 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The effect of temperature on the structural, electronic and optical properties of dense tetrahedral amorphous carbon made of similar to 80% sp(3)-bonded atoms is investigated using a combination of the classical Monte Carlo technique and density functional theory. A structural transformation accompanied by a slight decrease of the sp(3) fraction is evidenced above a temperature of about 600 degrees C. A structural analysis in combination with energy-loss near-edge structure calculations shows that beyond this temperature, the sp(2)-bonded C sites arrange themselves so as to enhance the conjugation of the p electrons. The Tauc optical band gap deduced from the calculated dielectric function shows major changes beyond this temperature in accordance with experimental results. Energy-loss near-edge structure and band gap calculations additionally reveal a massive destabilization of the of sp(3) bonding phase in favour of sp(2) bonding at a temperature of about 1300 degrees C which agrees very well with the reported value of 1100 degrees C. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000252922900026 |
Publication Date |
2007-12-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2008 IF: 1.900 |
Call Number |
UA @ lucian @ c:irua:67461 |
Serial |
840 |
Permanent link to this record |
|
|
|
Author |
Singh, K.; Maignan, A.; Simon, C.; Kumar, S.; Martin, C.; Lebedev, O.; Turner, S.; Van Tendeloo, G. |
Title |
Magnetodielectric CuCr0.5V0.5O2 : an example of a magnetic and dielectric multiglass |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
22 |
Pages |
226002-226002,4 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The complex dielectric susceptibility and spin glass properties of polycrystalline CuCr0.5V 0.5O2 delafossite have been investigated. Electron diffraction, high resolution electron microscopy and electron energy loss spectroscopy show that the Cr3+ and V 3+ magnetic cations are randomly distributed on the triangular network of CdI2-type layers. In contrast to CuCrO2, CuCr0.5V 0.5O2 exhibits two distinctive (magnetic and electric) glassy states evidenced by memory effects in electric and magnetic susceptibilities. A large magnetodielectric coupling is observed at low temperature. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000304873300027 |
Publication Date |
2012-05-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
19 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:98380 |
Serial |
1916 |
Permanent link to this record |
|
|
|
Author |
Zhang, H.; Salje, E.K.H.; Schryvers, D.; Bartova, B. |
Title |
The martensitic phase transition in Ni-Al: experimental observation of excess entropy and heterogeneous spontaneous strain |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
20 |
Issue |
5 |
Pages |
055220,1-7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000252923400023 |
Publication Date |
2008-01-19 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
|
Notes |
Multimat (MRTN-CT-2004-505226) |
Approved |
Most recent IF: 2.649; 2008 IF: 1.900 |
Call Number |
UA @ lucian @ c:irua:67710 |
Serial |
1948 |
Permanent link to this record |
|
|
|
Author |
Nistor, L.C.; Nistor, S.V.; Dinca, G.; Georgeoni, P.; van Landuyt, J.; Manfredotti, C.; Vittone, E. |
Title |
Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
14 |
Issue |
44 |
Pages |
10983-10988 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp(3) bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 +/- 15 mJ m(-2) is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000179541700114 |
Publication Date |
2002-10-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2002 IF: 1.775 |
Call Number |
UA @ lucian @ c:irua:103328 |
Serial |
2061 |
Permanent link to this record |
|
|
|
Author |
Simoen, E.; Loo, R.; Claeys, C.; de Gryse, O.; Clauws, P.; van Landuyt, J.; Lebedev, O. |
Title |
Optical spectroscopy of oxygen precipitates in heavily doped p-type silicon |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Journal of physics : condensed matter
T2 – Conference on Extended Defects in Semiconductors (EDS 2002), JUN 01-06, 2002, BOLOGNA, ITALY |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
14 |
Issue |
48 |
Pages |
13185-13193 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Results are presented on the photoluminescence (PL) characterization of heavily doped p(+) Czochralski silicon, which has been subjected to a two-step, oxygen precipitation heat treatment. It will be shown that the presence of oxygen precipitates gives rise to the D1, D2 and D5 lines, where the energy of the D1 line shifts to lower values for a stronger degree of precipitation. The occurrence of these PL features is also a function of the boron concentration in the p(+) material. The PL results are compared with Fourier transform infrared absorption data and with transmission electron microscope, results. From this, it is concluded that PL has a good potential for use in the assessment of oxygen precipitation in heavily doped silicon. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000180091100068 |
Publication Date |
2002-11-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2002 IF: 1.775 |
Call Number |
UA @ lucian @ c:irua:103326 |
Serial |
2477 |
Permanent link to this record |
|
|
|
Author |
Zelaya, E.; Tolley, A.; Condo, A.M.; Schumacher, G. |
Title |
Swift heavy ion irradiation of Cu-Zn-Al and Cu-Al-Ni alloys |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
21 |
Issue |
18 |
Pages |
185009-185009,8 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The effects produced by swift heavy ions in the martensitic (18R) and austenitic phase (beta) of Cu based shape memory alloys were characterized. Single crystal samples with a surface normal close to [210](18R) and [001](beta) were irradiated with 200 MeV of Kr(15+), 230 MeV of Xe(15+), 350 and 600 MeV of Au(26+) and Au(29+). Changes in the microstructure were studied with transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). It was found that swift heavy ion irradiation induced nanometer sized defects in the 18R martensitic phase. In contrast, a hexagonal close-packed phase formed on the irradiated surface of beta phase samples. HRTEM images of the nanometer sized defects observed in the 18R martensitic phase were compared with computer simulated images in order to interpret the origin of the observed contrast. The best agreement was obtained when the defects were assumed to consist of local composition modulations. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000264934400014 |
Publication Date |
2009-03-25 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
8 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
Call Number |
UA @ lucian @ c:irua:94551 |
Serial |
3399 |
Permanent link to this record |
|
|
|
Author |
Wang, J.; Shin, Y.; Gauquelin, N.; Yang, Y.; Lee, C.; Jannis, D.; Verbeeck, J.; Rondinelli, J.M.; May, S.J. |
Title |
Physical properties of epitaxial SrMnO2.5−δFγoxyfluoride films |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
31 |
Issue |
36 |
Pages |
365602 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Recently, topotactic fluorination has become an alternative way of doping epitaxial perovskite oxides through anion substitution to engineer their electronic properties instead of the more commonly used cation substitution. In this work, epitaxial oxyfluoride SrMnO2.5−δ F γ films were synthesized via topotactic fluorination of SrMnO2.5 films using polytetrafluoroethylene as the fluorine source. Oxidized SrMnO3 films were also prepared for comparison with the fluorinated samples. The F content, probed by x-ray photoemission spectroscopy, was systematically controlled by adjusting fluorination conditions. Electronic transport measurements reveal that increased F content (up to γ = 0.14) systematically increases the electrical resistivity, despite the nominal electron-doping induced by F substitution for O in these films. In contrast, oxidized SrMnO3 exhibits a decreased resistivity and conduction activation energy. A blue-shift of optical absorption features occurs with increasing F content. Density functional theory calculations indicate that F acts as a scattering center for electronic transport, controls the observed weak ferromagnetic behavior of the films, and reduces the inter-band optical transitions in the manganite films. These results stand in contrast to bulk electron-doped La1−x Ce x MnO3, illustrating how aliovalent anionic substitutions can yield physical behavior distinct from A-site substituted perovskites with the same nominal B-site oxidation states. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000472232000002 |
Publication Date |
2019-09-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
5 |
Open Access |
|
Notes |
Work at Drexel was supported by the National Science Foundation (NSF), grant number CMMI-1562223. Thin film synthesis utilized deposition instrumentation acquired through an Army Research Office DURIP grant (W911NF-14-1-0493). Y.S and J.M.R. were supported by NSF (Grant No. DMR-1454688). Calculations were performed using the QUEST HPC Facility at Northwestern, the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF Grant No. ACI-1053575, and the Center for Nanoscale Materials (Carbon Cluster). Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. J.V. and N. G. acknowledge funding from a GOA project “Solarpaint” of the University of Antwerp. D.J. acknowledges funding from FWO project G093417N from the Flemish fund for scientific research. |
Approved |
Most recent IF: 2.649 |
Call Number |
EMAT @ emat @UA @ admin @ c:irua:161174 |
Serial |
5293 |
Permanent link to this record |
|
|
|
Author |
Dixit, H.; Saniz, R.; Cottenier, S.; Lamoen, D.; Partoens, B. |
Title |
Electronic structure of transparent oxides with the Tran-Blaha modified Becke-Johnson potential |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
24 |
Issue |
20 |
Pages |
205503-205503,9 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
We present electronic band structures of transparent oxides calculated using the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential. We studied the basic n-type conducting binary oxides In2O3, ZnO, CdO and SnO2 along with the p-type conducting ternary oxides delafossite CuXO2 (X = Al, Ga, In) and spinel ZnX2O4 (X = Co, Rh, Ir). The results are presented for calculated band gaps and effective electron masses. We discuss the improvements in the band gap determination using TB-mBJ compared to the standard generalized gradient approximation (GGA) in density functional theory (DFT) and also compare the electronic band structure with available results from the quasiparticle GW method. It is shown that the calculated band gaps compare well with the experimental and GW results, although the electron effective mass is generally overestimated. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000303507100009 |
Publication Date |
2012-04-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
113 |
Open Access |
|
Notes |
Iwt; Fwo |
Approved |
Most recent IF: 2.649; 2012 IF: 2.355 |
Call Number |
UA @ lucian @ c:irua:98222 |
Serial |
1017 |
Permanent link to this record |
|
|
|
Author |
Dixit, H.; Lamoen, D.; Partoens, B. |
Title |
Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
25 |
Issue |
3 |
Pages |
035501-35505 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000313100500010 |
Publication Date |
2012-12-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
|
Notes |
Fwo |
Approved |
Most recent IF: 2.649; 2013 IF: 2.223 |
Call Number |
UA @ lucian @ c:irua:105296 |
Serial |
2801 |
Permanent link to this record |
|
|
|
Author |
Dixit, H.; Saniz, R.; Lamoen, D.; Partoens, B. |
Title |
The quasiparticle band structure of zincblende and rocksalt ZnO |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
22 |
Issue |
12 |
Pages |
125505,1-125505,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
We present the quasiparticle band structure of ZnO in its zincblende (ZB) and rocksalt (RS) phases at the Γ point, calculated within the GW approximation. The effect of the pd hybridization on the quasiparticle corrections to the band gap is discussed. We compare three systems, ZB-ZnO which shows strong pd hybridization and has a direct band gap, RS-ZnO which is also hybridized but includes inversion symmetry and therefore has an indirect band gap, and ZB-ZnS which shows a weaker hybridization due to a change of the chemical species from oxygen to sulfur. The quasiparticle corrections are calculated with different numbers of valence electrons in the Zn pseudopotential. We find that the Zn20 + pseudopotential is essential for the adequate treatment of the exchange interaction in the self-energy. The calculated GW band gaps are 2.47 eV and 4.27 eV respectively, for the ZB and RS phases. The ZB-ZnO band gap is underestimated compared to the experimental value of 3.27 by ~ 0.8 eV. The RS-ZnO band gap compares well with the experimental value of 4.5 eV. The underestimation for ZB-ZnO is correlated with the strong pd hybridization. The GW band gap for ZnS is 3.57 eV, compared to the experimental value of 3.8 eV. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000275496600010 |
Publication Date |
2010-03-13 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
53 |
Open Access |
|
Notes |
Iwt; Fwo; Bof-Nio |
Approved |
Most recent IF: 2.649; 2010 IF: 2.332 |
Call Number |
UA @ lucian @ c:irua:81531 |
Serial |
2802 |
Permanent link to this record |
|
|
|
Author |
Chen, Y.; Croitoru, M.D.; Shanenko, A.A.; Peeters, F.M. |
Title |
Superconducting nanowires: quantum confinement and spatially dependent Hartree-Fock potential |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
21 |
Issue |
43 |
Pages |
435701,1-435701,7 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
Abstract |
It is well known that, in bulk, the solution of the Bogoliubovde Gennes equations is the same whether or not the HartreeFock term is included. Here the HartreeFock potential is position independent and so gives the same contribution to both the single-electron energies and the Fermi level (the chemical potential). Thus, the single-electron energies measured from the Fermi level (they control the solution) stay the same. This is not the case for nanostructured superconductors, where quantum confinement breaks the translational symmetry and results in a position-dependent HartreeFock potential. In this case its contribution to the single-electron energies depends on the relevant quantum numbers. We numerically solved the Bogoliubovde Gennes equations with the HartreeFock term for a clean superconducting nanocylinder and found a shift of the curve representing the thickness-dependent oscillations of the critical superconducting temperature to larger diameters. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000270642700012 |
Publication Date |
2009-10-09 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2009 IF: 1.964 |
Call Number |
UA @ lucian @ c:irua:79162 |
Serial |
3360 |
Permanent link to this record |
|
|
|
Author |
Dabaghmanesh, S.; Saniz, R.; Amini, M.N.; Lamoen, D.; Partoens, B. |
Title |
Perovskite transparent conducting oxides : an ab initio study |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
25 |
Issue |
41 |
Pages |
415503 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
We present an ab initio study of the electronic structure and of the formation energies of various point defects in BaSnO3 and SrGeO3. We show that La and Y impurities substituting Ba or Sr are shallow donors with a preferred 1 + charge state. These defects have a low formation energy within all the suitable equilibrium growth conditions considered. Oxygen vacancies behave as shallow donors as well, preferring the 2 + charge state. Their formation energies, however, are higher in most growth conditions, indicating a limited contribution to conductivity. The calculated electron effective mass in BaSnO3, with a value of 0.21 me, and the very high mobility reported recently in La-doped BaSnO3 single-crystals, suggest that remarkably low scattering rates can be achieved in the latter. In the case of SrGeO3, our results point to carrier density and mobility values in the low range for typical polycrystalline TCOs, in line with experiment. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000324920400011 |
Publication Date |
2013-09-24 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
17 |
Open Access |
|
Notes |
FWO;Hercules |
Approved |
Most recent IF: 2.649; 2013 IF: 2.223 |
Call Number |
UA @ lucian @ c:irua:110495 |
Serial |
2574 |
Permanent link to this record |
|
|
|
Author |
Van Tendeloo, G.; Lebedev, O.I.; Collart, O.; Cool, P.; Vansant, E.F. |
Title |
Structure of nanoscale mesoporous silica spheres? |
Type |
A1 Journal article |
Year |
2003 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
15 |
Issue |
|
Pages |
S3037-S3046 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
|
Publication Date |
0000-00-00 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2003 IF: 1.757 |
Call Number |
UA @ lucian @ c:irua:46265 |
Serial |
3313 |
Permanent link to this record |
|
|
|
Author |
Titantah, J.T.; Lamoen, D.; Neyts, E.; Bogaerts, A. |
Title |
The effect of hydrogen on the electronic and bonding properties of amorphous carbon |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
18 |
Issue |
48 |
Pages |
10803-10815 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000242650600008 |
Publication Date |
2006-11-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984;1361-648X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
13 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.649; 2006 IF: 2.038 |
Call Number |
UA @ lucian @ c:irua:60468 |
Serial |
816 |
Permanent link to this record |
|
|
|
Author |
de de Meux, A.J.; Pourtois, G.; Genoe, J.; Heremans, P. |
Title |
Origin of the apparent delocalization of the conduction band in a high-mobility amorphous semiconductor |
Type |
A1 Journal article |
Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
Volume |
29 |
Issue |
25 |
Pages |
255702 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
In this paper, we show that the apparent delocalization of the conduction band reported from first-principles simulations for the high-mobility amorphous oxide semiconductor InGaZnO4 (a-IGZO) is an artifact induced by the periodic conditions imposed to the model. Given a sufficiently large unit-cell dimension (over 40 angstrom), the conduction band becomes localized. Such a model size is up to four times the size of commonly used models for the study of a-IGZO. This finding challenges the analyses done so far on the nature of the defects and on the interpretation of numerous electrical measurements. In particular, we re-interpret the meaning of the computed effective mass reported so far in literature. Our finding also applies to materials such as SiZnSnO, ZnSnO, InZnSnO, In2O3 or InAlZnO4 whose models have been reported to display a fully delocalized conduction band in the amorphous phase. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
London |
Editor |
|
Language |
|
Wos |
000402434900002 |
Publication Date |
2017-02-15 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.649 |
Times cited |
5 |
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 2.649 |
Call Number |
UA @ lucian @ c:irua:144183 |
Serial |
4676 |
Permanent link to this record |