Scientific Commons: Christian Van Haesendonck

We have combined electron heating experiments and noise thermometry to perform quantitative measurements of the thermopower in mesoscopic samples. This new measuring technique allows us to detect...

Inhomogeneous splitting of impurity-spin energy levels in mesoscopic wires (1998)

Fomin, VM, Gladilin, VN, Devreese, JT, Van Haesendonck, Christian; U0011549, Neuttiens, G

The Hamiltonian, which describes the surface-induced anisotropy for impurity spin in mesoscopic wires of dilute magnetic alloys, is derived for the wires with a rectangular cross-section and rough...

Thermoelectric effects in mesoscopic AuFe spin-glass wires (1998)

Neuttiens, G, Eom, J, Strunk, C, Pattyn, Hugo; U0017037, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, ...

Recently we reported on the differential resistance R(I) = dV/dI of narrow AuFe spin-glass wires (Phys. Rev. Let., 77 (1996) 2276). Surprisingly, R(I) nas found to be asymmetric in I for the smallest...

Low temperature force microscopy based on piezoresistive cantilevers operating at a higher flexural mode (1998)

Volodin, A, Van Haesendonck, Christian; U0011549

We present a method to considerably enhance the sensitivity of low-temperature force microscopy based on commercially available piezoresistive cantilevers. The sensitivity has been increased by using...

Influence of resonant tunneling on the imaging of atomic defects on InAs(110) surfaces by low-temperature scanning tunneling microscopy (1998)

Depuydt, A, Maslova, NS, Panov, VI, Rakov, VV, Savinov, SV, Van Haesendonck, Christian; U0011549

We have used a low-temperature scanning tunneling microscope (STM) to study the surface of heavily doped semiconductor InAs crystals. The crystals are cleaved in situ along the (110) plane. Apart...

Extrinsic origins of electrical transport anomalies near the superconducting transition in mesoscopic aluminum lines (1998)

Burk, B, Chien, CJ, Chandrasekhar, V, Strunk, C, Bruyndoncx, Vital; U0011761, Van Haesendonck, Christian; U0011549, ...

We investigate whether inadvertent noise currents may induce the previously reported resistive peak and negative differential resistance (dV/dI) anomalies near the superconducting transition in...

Scanning tunneling spectroscopy of charge effects on semiconductor surfaces and atomic clusters (1998)

Maslova, NS, Oreshkin, SI, Panov, VI, Savinov, SV, Depuydt, A, Van Haesendonck, Christian; U0011549

We have used scanning tunneling microscopy and scanning tunneling spectroscopy at liquid helium temperature to study the electronic structure of in situ cleaved, (110) oriented surfaces of InAs...

Logarithmic divergence of the electrical resistivity in the metal hydride YH3-delta (1997)

Huiberts, JN, Griessen, R, Wijngaarden, RJ, Kremers, M, Van Haesendonck, Christian; U0011549

As reported earlier, the metal hydride YHx reveals spectacular switchable optical properties. In this Letter we report on another remarkable property of the hydrogen deficient YH3-delta trihydride...

Nanowire bonding with the scanning tunneling microscope (1997)

Van Haesendonck, Christian; U0011549, Stockman, L, Vullers, RJM, Bruynseraede, Yvan; U0011882, Langer, L, Bayot, V, ...

We have developed a reliable lithographic method to pattern thin gold films by locally exposing a thin layer of an electron beam resist with the tip of a scanning tunneling microscope (STM). The...

Low-temperature scanning tunneling microscope for investigations in magnetic fields (1997)

Vasilev, SI, Oreshkin, SI, Panov, VP, Savinov, SV, Van Haesendonck, Christian; U0011549, Depuydt, A

A scanning tunneling microscope (STM), equipped with an attachment for in situ sample cleavage and capable of low-temperature measurements in the presence of a strong magnetic field, is described,...

Size distribution and magnetic behavior of lead inclusions in silicon single crystals (1997)

Milants, K, Verheyden, J, Barancira, T, Deweerd, W, Pattyn, Hugo; U0017037, Bukshpan, S, ...

The size distribution of Pb inclusions formed by high-dose ion implantation in crystalline Si has been studied with a variety of experimental techniques. Results obtained from small angle x-ray...

Fluxoid quantization effects in superconducting mesoscopic Al multiloop structures (1996)

Bruyndoncx, Vital; U0011761, Strunk, C, Moshchalkov, VV, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We have studied fluxoid quantization effects in mesoscopic Al samples consisting of a small number of square loops. In short microladders a pronounced substructure of the Little-Parks oscillations...

Nonlocal effects in mesoscopic superconducting aluminum structures (1996)

Strunk, C, Bruyndoncx, Vital; U0011761, Moshchalkov, VV, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Jonckheere, R

We have measured the magnetoresistance and the magnetic phase boundary T-c(B) of mesoscopic superconducting Al structures containing a loop. The structures were designed to study the nonlocal...

Asymmetric nonlinear differential resistance of mesoscopic AuFe spin-glass wires (1996)

Eom, J, Neuttiens, G, Strunk, C, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Chandrasekhar, V

We have measured the differential resistance R = dV/dI of mesoscopic AuFe wires as a function of temperature T and dc current bias I. R(T) shows a maximum at a temperature T-m similar to 1-4 K,...

Extracellular striatal dopamine and glutamate after decortication and kainate receptor stimulation, as measured by microdialysis (1996)

Smolders, I, Sarre, S, Van Haesendonck, Christian; U0011549, Ebinger, G, Michotte, Y

Disruption of corticostriatal glutamate input in the striatum decreased significantly extracellular striatal glutamate and dopamine levels. Local administration of 300 mu M concentration of...

Absence of size dependence in the spin-glass resistivity of AuFe wires? (1996)

Neuttiens, G, Eom, J, Strunk, C, Chandrasekhar, V, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We report on the low-temperature resistivity rho(T) of AuFe spin-glass wires with a thickness around 20 nm and a linewidth varying between 300 mu m and 150 nm. The observed linewidth dependence of...

Structural characterization of thin films and multilayer structures (1996)

Temst, Kristiaan; U0016278, Van Bael, Margriet; U0002550, Baert, M, Rosseel, E, Bruyndoncx, Vital; U0011761, Strunk, C, ...

Atomic force microscopy has been used to study the structure, down to the nanoscale, of thin-film and multilayer samples. Due to the fact that atomic force microscopy is not restricted to conducting...

Nonlocality and magnetic flux sensitivity of superconducting mesoscopic aluminium loops (1996)

Strunk, C, Bruyndoncx, Vital; U0011761, Van Haesendonck, Christian; U0011549, Moshchalkov, VV, Bruynseraede, Yvan; U0011882, Jonckheere, R

We have measured the magnetoresistance and the magnetic phase boundaries T-c(B) of mesoscopic superconducting structures containing an Al loop. The structures were designed to study the nonlocal...

Quantum transport in a multiwalled carbon nanotube (1996)

Langer, L, Bayot, V, Grivei, E, Issi, JP, Heremans, JP, Olk, CH, ...

We report on electrical resistance measurements of an individual carbon nanotube down to a temperature T = 20 mK. The conductance exhibits a lnT dependence and saturates at low temperature. A...

Noise current induced electrical transport anomalies near the superconducting transition in mesoscopic aluminum lines (1996)

Burk, B, Chien, CJ, Chandrasekhar, V, Strunk, C, Bruyndoncx, Vital; U0011761, Van Haesendonck, Christian; U0011549, ...

We investigate whether unintentionally applied currents may have induced the previously reported resistive and current-voltage characteristic anomalies near the superconducting transition temperature...

Novel asymmetry in the differential resistance of AuFe spin-glass wires (1996)

Eom, J, Neuttiens, G, Strunk, C, Van Haesendonck, Christian; U0011549, Verheyden, J, Pattyn, Hugo; U0017037, ...

We have measured the differential resistance R = dV/dI of mesoscopic AuFe wires as a function of temperature T and dc current bias I. As a function of I, the low temperature resistance R(I) shows a...

Fluxoid quantization in mesoscopic Al multiloop structures (1996)

Bruyndoncx, Vital; U0011761, Strunk, C, Moshchalkov, VV, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

Mesoscopic superconducting loops exhibit a well-known h/2e periodic modulation of the transition temperature T-c with the enclosed magnetic flux Phi, which is due to the fluxoid quantization. We have...

Nonlocal effects in mesoscopic superconducting Al structures (1996)

Strunk, C, Bruyndoncx, Vital; U0011761, Moshchalkov, VV, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We have measured the magnetoresistance R(B) and the magnetic phase boundaries T-c(B) of a mesoscopic superconducting Al loop and of the leads connected to the loop. Pronounced oscillations with flux...

Resistance anomalies in mesoscopic superconducting Al structures (1996)

Strunk, C, Bruyndoncx, Vital; U0011761, Burk, B, Chien, CJ, Van Haesendonck, Christian; U0011549, Moshchalkov, VV, ...

We show that the recently reported anomalous resistance peaks near the superconducting transition of quasi-one-dimensional mesoscopic Al structures can be induced by applying either radio-frequency...

Nanolithographic patterning of au films with a scanning tunneling microscope (1995)

Van Haesendonck, Christian; U0011549, Stockman, L, Neuttiens, G, Strunk, C, Bruynseraede, Yvan; U0011882

Electrical measurements on submicronic synthetic conductors - carbon nanotubes (1995)

Langer, L, Stockman, L, Heremans, Jp, Bayot, V, Olk, Ch, Van Haesendonck, Christian; U0011549, ...

The synthesis of very small samples has raised the need for a drastic miniaturization of the classical four-probe technique in order to realize electrical resistance measurements. Two methods to...

Effect of sample topology on the critical fields of mesoscopic superconductors (1995)

Moshchalkov, Vv, Gielen, L, Strunk, C, Jonckheere, R, Qiu, X, Van Haesendonck, Christian; U0011549, ...

THE superconducting state of a material can be suppressed by either increasing the temperature (T) or applying a magnetic field (H). For bulk samples, the form of the H-T phase boundary is mainly...

Effect of the sample topology on superconducting critical parameters (1994)

Moshchalkov, Vv, Gielen, L, Strunk, C, Jonckheere, R, Qiu, X, Van Haesendonck, Christian; U0011549, ...

The magnetic field (H) - temperature (T) phase boundary has been measured for mesoscopic superconducting samples of different topology (lines, loops and dots). Both the quantization effects and the...

Evidence for a brick wall microstructure in epitaxial yba2cu3ox films (1994)

Gao, Zx, Heyvaert, I, Wuyts, B, Osquiguil, E, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We have measured the in-plane (ab plane) critical current density J(c) in sputtered, c-axis oriented YBa2Cu3Ox films as a function of the oxygen content x. The important reduction of J(c) with...

Electrical-resistance of a carbon nanotube bundle (1994)

Langer, L, Stockman, L, Heremans, Jp, Bayot, V, Olk, Ch, Van Haesendonck, Christian; U0011549, ...

The first direct electrical resistance measurements performed on a single carbon nanotube bundle from room temperature down to 0.3 K and in magnetic fields up to 14 T are reported. From the...

Absence of size dependence of the kondo resistivity (1994)

Chandrasekhar, V, Santhanam, P, Penebre, Na, Webb, Ra, Vloeberghs, H, Van Haesendonck, Christian; U0011549, ...

We have measured the low temperature resistivity of AuFe wires in the dilute magnetic impurity limit as a function of wire width, temperature, and magnetic field. When the width dependence of the...

Size dependence of the kondo resistivity in aufe wires (1994)

Chandrasekhar, V, Santhanam, P, Penebre, Na, Webb, Ra, Vloeberghs, H, Van Haesendonck, Christian; U0011549, ...

We have measured the temperature and magnetic field dependence of the low temperature resistivity of Au wires with dilute (approximately 50 ppm) Fe impurities as a function of wire width. In contrast...

An oscillatory transition from normal to superconducting state in mesoscopic al samples (1994)

Moshchalkov, Vv, Gielen, L, Dhalle, M, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

Temperature dependence of resistance, R(T), has been measured for different perpendicular magnetic fields in mesoscopic Al squares. An anomalous oscillatory resistive transition into the...

Quantum interference and confinement phenomena in mesoscopic superconducting systems (1994)

Moshchalkov, VV, Gielen, L, Baert, M, Metlushko, V, Neuttiens, G, Strunk, C, ...

The superconducting field (H)-temperature (T) phase boundary has been measured in mesoscopic Al samples of different topology: lines, open and filld squares, which were made under the same conditions...

Submicrometer lithographic patterning of thin gold-films with a scanning tunneling microscope (1993)

Stockman, L, Neuttiens, G, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

A scanning tunneling microscope (STM) has been used to locally expose Langmuir-Blodgett layers of a negative electron beam resist (omega-tricosenoic acid) on top of a thin gold film. The STM operates...

Quantum interference in a mesoscopic superconducting loop (1993)

Moshchalkov, Vv, Gielen, L, Dhalle, M, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

THE classical superconducting quantum interference device (SQUID) is based on the Josephson effect1, and usually consists of a macroscopic superconducting loop with two artificial weak links...

Scanning tunneling microscopy observation of self-affine fractal roughness in ion-bombarded film surfaces (1993)

Krim, J, Heyvaert, I, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We describe a straightforward method for obtaining a precise value for the fractal dimension (self-affine scaling exponent) of a surface, via scanning tunneling microscopy. It is applied to...

Anomalous little-parks oscillations in mesoscopic loops (1992)

Vloeberghs, H, Moshchalkov, Vv, Van Haesendonck, Christian; U0011549, Jonckheere, R, Bruynseraede, Yvan; U0011882

Anomalous resistance oscillations have been observed in mesoscopic superconducting Al loops. As for the classical Little-Parks effect, the oscillation period is governed by the superconducting...

Etching of screw dislocations in yba2cu3o7 films with a scanning tunneling microscope (1992)

Heyvaert, I, Osquiguil, E, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

We report on the systematic unrolling of screw dislocations with the scanning tunneling microscope at the surfaces of sputtered, c-axis oriented YBa2Cu3O7 films. The etching is dominated by field...

The magnetic-moment relaxation in oxygen-deficient yba2cu3ox (1992)

Libbrecht, S, Maenhoudt, M, Van Haesendonck, Christian; U0011549, Osquiguil, E, Bruynseraede, Yvan; U0011882

The magnetic moment relaxation in polycrystalline YBa2Cu3Ox material has been studied using zero-field-cooled measurements. The temperature dependence of the relaxation rate shows a field-dependent...

Topographic study of thin gold-films grown on sio2 (1992)

Stockman, L, Vloeberghs, H, Heyvaert, I, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

The surface topography of thin Au films (thickness approximately 10 nm) has been studied by STM in air. The films are obtained by flash evaporation onto liquid-nitrogen cooled, oxidized Si...

Electron interference in mesoscopic au loops (1991)

Vloeberghs, H, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Verbruggen, Ah, Holweg, Pam, Radelaar, S

We have studied electron interference effects in mesoscopic Au loops. For high magnetic fields, we clearly observe Aharonov-Bohm h/e oscillations and much weaker second harmonic h/2e oscillations. At...

Magnetic order in mesoscopic metal-films (1991)

Van Haesendonck, Christian; U0011549, Vloeberghs, H, Bruynseraede, Yvan; U0011882, Verbruggen, Ah, Radelaar, S

Using Fe doped Au films we show that the interference effects which occur between diffusively scattered electron waves are extremely sensitive to the presence of magnetic impurities. In macroscopic...

Metal-insulator-transition in thin tiox films (1991)

Vlekken, C, Vangrunderbeek, J, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

Conductivity and electron tunneling measurements are reported for amorphous, oxygen rich Ti films in the vicinity of the Anderson metal-insulator transition. In the metallic films the conductivity...

Correlation between critical current and resistivity in yba2cu3o7 (1991)

Dhalle, M, Boon, Willy; U0020555, Osquiguil, E, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Kwarciak, J, ...

Critical current versus temperature measurements were carried out in ceramic YBa2Cu3O7 samples. The samples were all prepared using the same sintering procedure, but starting from powders obtained by...

Lock-in transition of flux-lines in layered superconductors (1991)

Vermeer, Aj, Degroot, Dg, Koeman, Nj, Griessen, R, Van Haesendonck, Christian; U0011549

In an attempt to prove the existence of a lock-in transition of flux-lines in layered superconductors, we have synthesised Nb/Cu multilayers by means of evaporation under ultra-high vacuum...

Fabrication of 35nm linewidth gold rings and observation of h/e and h/2e magnetoconductance oscillations (1991)

Verbruggen, Ah, Holweg, Pam, Vloeberghs, H, Van Haesendonck, Christian; U0011549, Romijn, J, Radelaar, S, ...

A detailed description is given of the fabrication of gold rings with a diameter of approximately 700 nm and a linewidth between 25 and 50 nm. The fabrication technique is based on electron beam...

Can atomic force microscopy tips be inspected by atomic force microscopy (1991)

Hellemans, Louis; U0009573, Waeyaert, K, Hennau, F, Stockman, L, Heyvaert, I, Van Haesendonck, Christian; U0011549

An attempt has been made to image prospective tips by atomic force microscopy. The apex of mounted diamond fragments and of traditional metallic tips was investigated by the same diamond probe. The...

Destruction of the spin-glass order in thin aufe films (1990)

Vloeberghs, H, Vranken, J, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882

A new method of synthesizing high-tc superconducting materials (1989)

Eggermont, T, Arkens, O, Beyne, E, Roggen, J, ...

Proton intercalation in reactively sputtered wo3 films (1988)

Vangrunderbeek, J, Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Vermeiren, P, Winckelmans, C, Leysen, R

Nonlocal electrical-properties in mesoscopic devices (1987)

Umbach, Cp, Santhanam, P, Van Haesendonck, Christian; U0011549, Webb, Ra

Resonant kondo scattering of weakly localized-electrons (1987)

Van Haesendonck, Christian; U0011549, Vranken, J, Bruynseraede, Yvan; U0011882

Coherent electron-scattering in mesoscopic metal-films (1987)

Van Haesendonck, Christian; U0011549, Bruynseraede, Yvan; U0011882, Laibowitz, R, Santhanam, P, Umbach, C, Washburn, S, ...