Institute for Nanoscale Physics and Chemistry INPAC

Leuven, Belgium

Institute for Nanoscale Physics and Chemistry INPAC

Leuven, Belgium
SEARCH FILTERS
Time filter
Source Type

Tryhuk V.V.,Brest State University | Ravinski A.F.,Brest State University | Ravinski A.F.,Bialystok Technical University | Makoed I.I.,Brest State University | And 2 more authors.
International Conference on Oxide Materials for Electronic Engineering, OMEE 2012 | Year: 2012

The Bi1-xGdxFeO3 (x = 0 - 0.2) ceramics were prepared by a solid-state reaction technique. Studies of magnetic and magnetoelectric properties were carried out. Due to the R3c → Pnma structural change, the spiral modulated spin structure collapses continuously with increasing Gd content and strongly enhances magnetization and magnetoelectric coefficient at x > 0.1. Studies of lattice dynamics of pure BiFeO3 were conducted ab-initio by means of density functional theory in order to shed light on ferroelectric instability. © 2012 IEEE.


Wu L.H.,Tsinghua University | Wu L.H.,Beijing National Center for Electronic Microscopy | Wu L.H.,Shanghai Aircraft Design and Research Institute | Zhang X.,Tsinghua University | And 6 more authors.
Applied Physics Letters | Year: 2011

Nonsaturating positive magnetoresistance (MR) of intrinsic bulk silicon (i-Si) was observed at forward bias, exhibiting an almost linear behavior at high magnetic fields (5 T


Lazenka V.V.,Institute for Nanoscale Physics and Chemistry INPAC | Zhang G.,Institute for Nanoscale Physics and Chemistry INPAC | Vanacken J.,Institute for Nanoscale Physics and Chemistry INPAC | Makoed I.I.,Brest State University | And 3 more authors.
Journal of Physics D: Applied Physics | Year: 2012

The crystal structure, dielectric, magnetic and magnetoelectric (ME) properties of Bi 1xGd xFeO 3 (BGFO, x=0, 0.05, 0.1, 0.15, 0.2) multiferroic ceramics have been studied. The substitution of bismuth by gadolinium induces a phase structural transition at x>0.1, which leads to the suppression of the spiral modulated spin structure and develops weak ferromagnetic properties in the BiFeO 3-based materials. Through studying the temperature/magnetic field dependence of the ME coefficient, we have revealed the effect of the substitution of Gd 3+ ions on the ME properties, and have demonstrated the possibility of manipulating the electric state in BGFO multiferroics by applying magnetic field at room temperature. © 2012 IOP Publishing Ltd.


Muzychenko D.A.,Moscow State University | Savinov S.V.,Moscow State University | Mantsevich V.N.,Moscow State University | Maslova N.S.,Moscow State University | And 3 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

By means of low-temperature scanning tunneling microscopy and scanning tunneling spectroscopy we demonstrate the existence of spatial oscillations in the local electron density of states of clean Ge (111) 2×1 surfaces. The oscillations appear exclusively in the vicinity of boundaries between domains with different atomic arrangements and are present only within a limited range of tunneling voltages approximately between 0.2 and 0.8 V. From the spectroscopy measurements we are able to extract the energy versus wave-vector dispersion relation of the spatial oscillations in the local electron density of states. Relying on a tight-binding based model, we are able to link the observed phenomena to two-dimensional Tamm surface states that are formed within the semiconductor band gap and that are scattered at domain boundaries where translational symmetry is broken. © 2010 The American Physical Society.


Schouteden K.,Institute for Nanoscale Physics and Chemistry INPAC | Volodin A.,Institute for Nanoscale Physics and Chemistry INPAC | Muzychenko D.A.,Moscow State University | Chowdhury M.P.,Institute for Nanoscale Physics and Chemistry INPAC | And 3 more authors.
Nanotechnology | Year: 2010

Discrete image-potential states (ISs) are revealed at double-walled carbon nanotubes by means of scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) in the distance-voltage z(V) spectroscopy mode. The nanotubes are supported by flat Au(111) substrates. Due to the high sensitivity of the hot IS electrons to local variations of the surface potential, they can be considered as a sensitive probe to investigate interactions with the supporting substrate and impurities or defects at the nanotube surface. ISs provide information on the local electronic structure as well as on the electron dynamics at supported nanotubes. © 2010 IOP Publishing Ltd.


Yamaguchi T.,Kansai University | Shimizu T.,Kansai University | Wang C.,Kansai University | Inada M.,Kansai University | And 4 more authors.
Materials Research Society Symposium Proceedings | Year: 2012

The macro and micro morphology of the Si surface, depending on noble metal ion concentration in etching solution, prepared by metal assisted etching were investigated. We defined the morphology of etched Si in four types, and developed the phase diagram of Si morphology. Mixture of silver nitrate (AgNO3) and hydrofluoric acid (HF) was used as an electroless-plating bath of Ag, as well as etching solution of Si. The morphology of the etched Si surface as function of concentration of AgNO3 in etching solution was observed by SEM. With increasing concentration of the AgNO3 in the etching solution, the surface of etched Si tended to be porous structure with very fine pores of a few nm (porous Si). When concentration of AgNO3 is low, single crystal Si nanowires with a smooth surface without pores were observed. © 2012 Materials Research Society.


Schouteden K.,Institute for Nanoscale Physics and Chemistry INPAC | Van Haesendonck C.,Institute for Nanoscale Physics and Chemistry INPAC
Journal of Physics Condensed Matter | Year: 2010

Deposition of Co atoms on Au(111) surfaces leads to the formation of self-organized bilayer Co nanowires at the step edges between adjacent narrow Au(111) terraces. Scanning tunneling microscopy and spectroscopy at low temperatures is used to probe the influence of the finite dimensions on the local density of states for both the Co wires and the narrow Au terraces. Confinement of Au surface state electrons to narrow Au terraces causes a shift of the Au surface state onset energy to higher energies. For the Co nanowires discrete energy levels are observed. Moreover, standing wave patterns occur at the surface of both the Au and the Co. The patterns increase in complexity with increasing energy. All Co nanowires formed at the edges of narrow Au terraces reveal a characteristic maximum in the local density of states at a significantly different energy when compared to the Co islands that are formed on large Au terraces. The experimental results can be interpreted in terms of a simple particle-in-a-box model. © 2010 IOP Publishing Ltd.


Kramer R.B.G.,Institute for Nanoscale Physics and Chemistry INPAC | Ataklti G.W.,Institute for Nanoscale Physics and Chemistry INPAC | Moshchalkov V.V.,Institute for Nanoscale Physics and Chemistry INPAC | Silhanek A.V.,Institute for Nanoscale Physics and Chemistry INPAC
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

A combination of scanning Hall microscopy and scanning ac-susceptibility measurements in superconducting stripes (ribbons) of width w<10μm was used to observe the dimensional phase transitions of the vortex lattice and its stability under alternating fields. At low dc magnetic fields applied perpendicularly to the plane of the stripes, vortices form a one-dimensional chain at the center of the stripes. Above a certain field H- (w), the vortex chain splits in two parallel rows displaced laterally in such a way that a zigzag vortex pattern is observed. By shaking the vortices with an external magnetic ac field and detecting their in-phase motion locally, we can identify the degree of mobility of each individual vortex. This technique allows us (i) to directly visualize the transition from intravalley (Campbell regime) to intervalley vortex motion as the amplitude of the ac modulation is increased and (ii) to accurately determine the temperature at which the vortex lattice freezes in a field-cooling experiment. © 2010 The American Physical Society.

Loading Institute for Nanoscale Physics and Chemistry INPAC collaborators
Loading Institute for Nanoscale Physics and Chemistry INPAC collaborators