http://lab-neel.grenoble.cnrs.fr/INDIVIDUS/givord.html

Dominique Givord

Laboratoire Louis Néel
25, Avenue des Martyrs BP 166
38042 - Grenoble Cedex 9, FRANCE
Room : D202C
Tel.: +33 (0)4 7688-1090
Fax.: +33 (0)4 7688-1191
givord@grenoble.cnrs.fr

Couches minces et nanostructures magnétiques

Le groupe Couches minces et nanostructures magnétiques  est un groupe de recherche du Laboratoire Louis Néel, impliqué dans la fabrication et l'étude de systèmes magnétiques sous forme de couches minces, nanostructures artificielles ou auto-organisées, et matériaux nanostructurés. Nous sommes particulièrement intéressés par les systèmes modèles, permettant d'étudier finement des phénomènes tels que le renversement d'aimantation, la magnéto-résistance, le couplage d'échange, l'anisotropie de surface/interface, etc.
Nanomagnetism and nanomaterials

Dominique Givord

Laboratoire Louis Néel, CNRS, BP 166, 38042- Grenoble-Cedex9, France

During the last ten years, the development of nanosize magnetic materials has been the source of the discovery of spectacular new phenomena, with potential applications in the fields of information technologies, telecommunication or medicine.

The usual concepts used to describe the magnetic properties of matter must be reconsidered at the nanoscale when the system dimensions are below the characteristic length-scales of magnetic interactions, i.e. of the order 2-3 nm or below. The atom magnetic moments tend to be enhanced, ferromagnetism may appear when it is not stable in the bulk and large magnetic anisotropy exists. These effects are explained by considering the modification of the atom environment which results from the reduced dimensions of the systems and surface contribution which are relatively more important than in the bulk.

The magnetization processes which describe the response of a magnetic system to an applied magnetic field are strongly affected at dimensions below that of the so-called magnetic walls, of the order of 5-20 nm. Although, in the bulk, magnetization processes are determined by the influence of defects, in individual nanoparticles, coherent rotation, a property of ideal systems, has been observed for the first time. The quantitative analysis of this process may reveal reversal by macroscopic quantum tunnelling. This is in particular the case of magnetic molecular clusters where a series of fascinating behaviours is observed.

Materials formed of an assembly of coupled nanograins form another family of nanomaterials, the properties of which are governed by the competition existing between intra-grain and inter-grain interactions. Their original behaviours may be described in terms of simple concepts, such as those of enhanced remanence, exchange-spring and exchange-bias. They have permitted the development of new families of functional magnetic materials.

Dominique Givord

Laboratoire Louis Néel
25, Avenue des Martyrs BP 166
38042 - Grenoble Cedex 9, FRANCE
Room : D202C
Tel.: +33 (0)4 7688-1090
Fax.: +33 (0)4 7688-1191
givord@grenoble.cnrs.fr

2003

X-ray super-cell crystallography of self-organized Co/Au(111) deposits
Fruchart O., Renaud G., Barbier A., Noblet M., Ulrich O., Deville J.P., Scheurer F., Mané-Mané J., Repain V., Baudot G., Rousset S.
Europhys. Lett. 63 (2), p. 275-281 (2003)
Abstract | Abstract (On-Line Journal)
Publication N° 101

Real-Time Monitoring of Growing Nanoparticles
Renaud G., Lazzari R., Revenant C., Barbier A., Noblet M., Ulrich O., Leroy F., Jupille J., Borensztein Y., Henry C., Deville J.P., Scheurer F., Mané-Mané J., Fruchart O.
Science 300 (5624), p. 1416-1419 (2003)
Abstract | Abstract (On-Line Journal) | PDF
Publication N° 94

Nucleation and surface diffusion in pulsed laser deposition of Fe on Mo(110)
Jubert P.O., Fruchart O., Meyer C.
Surf. Sci. 522 (1-3), p. 8-16 (2003)
Abstract | Abstract (On-Line Journal)
Publication N° 72

New model for the magnetic structure of the marokite-type oxide CaMn2O4
Zouari S., Ranno L., Cheikh-Rouhou A., Isnard O., Pernet M., Wolfers P., Strobel P.
J. Alloys Comp. 353 , p. 5-11 (2003)
Abstract
Publication N° 137

Nanomagnétisme : des domaines confinés au magnétisme moléculaire
Fruchart O., Bonet E., Toussaint J.C., Wernsdorfer W.
Bull. Soc. Fr. Phys. 139 , p. 11-17 (2003)
Abstract | PDF
Publication N° 95

Local anisotropy in strained manganite thin films
Souza-Neto N.M., Ramos A.Y., Tolentino H.C.N., Favre-Nicolin E., Ranno L.
Appl. Phys. Lett. 83 (17), p. 3587-3589 (2003)
Abstract
Publication N° 136

Flux-closure-domain states and demagnetizing energy determination in sub-micron size magnetic dots
Jubert P.O., Toussaint J.C., Fruchart O., Meyer C., Samson Y.
Europhys. Lett. 63 (1), p. 135-141 (2003)
Abstract
Publication N° 97

Étude de plasmas générés par laser, soumis à des champs magnétique et électrique. Utilisation possible en techniques de dépôts.
Ducruet C.
Thesis, Université Joseph Fourier, Grenoble (2003)
Abstract | Abstract (On-Line Journal) | PDF
Publication N° 138

Beating the superparamagnetic limit with exchange bias
Skumryev V., Stoyanov S., Zhang Y., Hadjipanayis G., Givord D., Nogués J.
Nature 423 , p. 850-853 (2003)
Abstract
Publication N° 98

An original route for the preparation of hard FePt
Hai N.H., Dempsey N.M., Veron M., Verdier M., Givord D.
J. Magn. Magn. Mater. 257 , p. L139(2003)
Abstract
Publication N° 82

2002

K. Fröhlich, D. Machajdík, V. Cambel, I. Kostic et S. Pignard
"Epitaxial growth of low-resisitivity RuO₂ films on (1102)-oriented Al₂O₃ substrate"
J. Cryst. Growth 235, 377 (2002).

O. Fruchart, P.-O. Jubert, C. Meyer, M. Klaua, J. Barthel et J. Kirschner
"Vertical self-organization of epitaxial magnetic nanostructures"
J. Magn. Magn. Mater. 239 (1-3), 224-227 (2002).  [Résumé]

O. Fruchart, G. Renaud, J.-P. Deville, A. Barbier, F. Scheurer, M. Klaua, J. Barthel, M. Noblet, O. Ulrich, J. Mané-Mané, et al.
"Self-organized growth of nanosized flat dots and vertical magnetic Co pillars on Au(111)"
J. Cryst. Growth 237-239 ((3)), 2035-2040 (2002).  [Résumé]

J. L. Garcia-Munoz, C. Frontera, M. A. G. Aranda, C. Ritter, A. Llobet, L. Ranno, M. Respaud, J. Vanacken et J. M. Broto
"Electronic and magnetic transitions in Bi-Sr-Mn-O oxides: high temperature charge-ordering"
J. Magn. Magn. Mater. 242-245, 645-647 (2002).

A. Giguère
"Préparation et étude des propriétés magnétiques et de transport de nanocomposites obtenus par déformation mécanique"
Thèse, Laboratoire Louis Néel (CNRS), Université Joseph Fourier, Grenoble (2002).

A. Giguère , N. H. Hai, N. Dempsey et D. Givord
"Preparation of microstructured and nanostructured magnetic materials by mechanical deformation"
J. Magn. Magn. Mater. 242-245, 581 (2002).

D. Givord, S. David, N. H. Haï, N. M. Dempsey et J.-C. Toussaint
"Prospects For Hard Magnetic Nanocomposites"
Proceedings of 16th Int. Workshop on RE magnets and their Applications, Delaware, Delaware, USA, 1058 (2002).

P.-O. Jubert, O. Fruchart et C. Meyer
"Magnetic properties of step-decorated Fe nanostripes and dots grown on Mo(110)"
J. Magn. Magn. Mater. 242-245 (1), 565-567 (2002).  [Résumé]

S. Kenane, E. Chainet, B. Nguyen, A. Kadri, N. Benbrahim et J. Voiron
"Giant magnetoresistance in Co-Ag granular films prepared by electrodeposition"
Electrochem. Comm. 4, 167 (2002).

S. Pokrant, O. Fruchart, C. Meyer et L. Ortega
"Growth of Tb(0001) on Nb and Mo(110) surfaces"
Surf. Sci. 506 (3), 235-242 (2002).  [Résumé]

S. Pokrant, C. Meyer, O. Fruchart et A. Sulpice
"Magnetic properties of Tb (0001) particles on Nb (110)"
J. Magn. Magn. Mater. 242-245 (1), 568-571 (2002).  [Résumé]

A. Y. Ramos, C. Giacomelli, A. Favre-Nicolin et L. Ranno
"Strain effects in epitaxially grown La_0.7Sr_0.3MnO₃ thin films"
Physica B 320 (1-4), 83-88 (2002).

L. Ranno, A. Llobet, R. Tiron et E. Favre-Nicolin
"Strain induced magnetic anisotropy in epitaxial manganite films"
Appl. Surf. Sci. 188 (1-2), 170-175 (2002).

D. H. Shin, L. Ranno et G. Suran
"Correlation between magnetic properties and Hall effect in CoZrGd films"
J. Magn. Magn. Mater. 242-245, 1178-1181 (2002).

G. Suciu, J. C. Toussaint et J. Voiron
"4f-3d exchange coupling in Gd/X/Co (X=Pt, Cr) multilayers"
J. Magn. Magn. Mater. 240, 229 (2002).

G. Suciu
"Contribution à l'étude du couplage d'échange entre couches de terres rares et de métaux de transition 3d à travers un métal non magnétique dans des multicouches"
Thèse, Laboratoire Louis Néel (CNRS), Université Joseph Fourier, Grenoble (2002).

H. Vincent, M. Audier, S. Pignard, G. Dezanneau et J.-P. Sénateur
"Crystal structure transformations of a magnetoresistive La_0,8MnO_3-d thin film"
J. Sol. State Chem.164 164, 177 (2002).

2001

G. Corbel, E. Suard, J. Voiron et M. Leblanc
"Hydrothermal synthesis and magnetic studies of transition metal ocerites M₃(BO₃)F₃ (M=Fe, Co, Ni)"
J. Magn. Magn. Mater. 234, 423 (2001).

N. M. Dempsey, L. Ranno, G. Givord, J. Gonzalo, R. Serna, G. T. Fei, A. K. Petford-Long, R. C. Doole et D. E. Hole
"Magnetic behavior of Fe:Al₂O₃ nanocomposite films produced by Pulsed Laser Deposition"
J. Appl. Phys. 90, 6268 (2001).

E. Favre-Nicolin, L. Ranno, C. Dubourdieu et M. Rosina
"Spin dependent tunneling in LaSrMnO/SrTiO superlattices"
Thin Solid Films 400, 165-168 (2001).

C. Frontera, J. L. Garcia-Munoz, A. Llobet, M. A. G. Aranda, C. Ritter, M. Respaud et J. Vanacken
"Room temperature charge and orbital ordering and phase coexistence in Mi0.5Sr0.5MnO3"
J. of Phys.: Cond. Mat. 13, 1071-1078 (2001).

O. Fruchart, B. Kevorkian et J.-C. Toussaint
"Micromagnetic model of non-collective magnetization reversal in ultrathin magnetic dots with in-plane uniaxial anisotropy"
Phys. Rev. B 63, 174418 (15 pages) (2001).  [Résumé]

J. L. Garcia-Munoz, C. Frontera, M. A. G. Aranda, A. Llobet et C. Ritter
"High-temperature orbital and charge ordering in Bi1/2Sr1/2MnO3"
Phys. Rev. B 63, 064415/1-4 (2001).

N. H. Hai, N. M. Dempsey et D. Givord
"Magnetism in Systems of Exchange Coupled Nanograins"
Europhys. J. B 24, 15 (2001).

P.-O. Jubert, O. Fruchart et C. Meyer
"Self-assembled growth of faceted epitaxial Fe(110) islands on Mo(110)/Al2O3(11-20)"
Phys. Rev. B 64, 115419 (10 pages) (2001).  [Résumé]

P. O. Jubert, O. Fruchart et C. Meyer
"Growth and magnetism of epitaxial self-assembled Fe nanostructures on a Mo(110) surface"
J. Magn. Magn. Mater. 226-230, 1842-1844 (2001).  [Résumé]

P.-O. Jubert, S. Jaren et C. Meyer
"Self-assembled magnetic nanostructures : Fe(110) islands on a Mo(110) surface"
Proceedings of NATO ASI on Magnetic Storage systems beyond 2000, Dordrecht, Netherlands, Vol. 41 (2001).

P.-O. Jubert
"Croissance et propriétés magnétiques de nanostructures épitaxiées auto-assemblées: le système Fe/Mo(110)"
Thèse, Laboratoire Louis Néel (CNRS), Université Joseph Fourier, Grenoble (2001).

A. Llobet, L. Ranno et J. Pierre
"Tuning Magnetotransport and Magnetic properties of La2/3Ca1/3MnO3 thin films using epitaxial strain"
Proceedings of EMMA'2000, Kiev, Ukraine, Vol. 373-376, 517-520 (2001).

J. L. Menendez, G. Armelles, F. Briones, A. Cebollada, F. Peiro, F. Guell, A. Cornet, M. L. Fernandez-Gubieda et C. Meyer
"Nitrogen incorporation effects in Fe(001) thin films"
J. Appl. Phys. 89, 6314 (2001).

W. Neubeck, C. Vettier, F. de Bergevin, F. Yakhou, D. Mannix, L. Ranno et T. Chatterji
"Orbital moment determination of simple transition metal oxides using X-ray diffraction"
J. Phys. Chem. Solids 62 (12), 2173-2180 (2001).

S. Pignard, K. Yu-Zhang, Y. Leprince-Wang, K. Han, H. Vincent et J. P. Sénateur
"Correlation between magnetoresistive properties and growth morphology of La1-xMnO3-d thin films deposited on SrTiO3, LaAlO3 and MgO"
Thin Solid Films 391, 21 (2001).

F. Reynaud, D. Mertz, F. Celestini, J. M. Debiere, A. M. Ghorayeb, P. Simon, A. Stepanov, J. Voiron et C. Delmas
"Orbital frustration at the origin of the magnetic behavior in LiNiO2"
Phys. Rev. Lett. 86, 3638 (2001).

N. Ryzhanova, C. Lacroix, A. Vedyayev, D. Bagrets et B. Dieny
"Adreev reflection in superconducting/spin-valve sandwiches"
J. Magn. Magn. Mater. 226-230, 750-751 (2001).

D. H. Shin, H. Niedoba et G. Suran
"Perpendicular anisotropy in a-CoGdZr films, induced by HDC applied during deposition"
IEEE Trans. Magn. 37, 1422-1425 (2001).

H. Vincent, M. Audier, S. Pignard, G. Dezanneau et J. P. Sénateur
"Relationships between crystal structure and magneto-transport properties in CMR thin films of lacunar lanthanum manganites"
J. Magn. Magn. Mater. 226-230, 788 (2001).

S. Zouari, L. Ranno, A. Cheikh-Rouhou, M. Pernet et P. Strobel
"Effect of A-cation size variance on structural and physical properties of praseodymium manganites Pr0.85(Na1-xKx)0.15MnO3"
Sol. Stat. Comm. 119 (8-9), 517-521 (2001).

2000

J. A. Bartkowska, J. Cisowski, J. Voiron, J. Heimann, M. Czaja et Z. Mazurak
"Magnetization and magnetic susceptibility of kunzite"
J. Magn. Magn. Mater. 221, 273 (2000).

O. Fruchart, M. Klaua, J. Barthel et J. Kirschner
"Growth of nanosized self-organized pillars of Co in Au(111) using an alternating deposition process"
Appl. Surf. Science 162-163, 529-536 (2000).  [Résumé]

B. Grevin, I. Maggio-Aprile, A. Bentzen, L. Ranno, A. Llobet et O. Fischer
"Local electronic transport in La0.7Sr0.3MnO3 thin films studied by scanning tunneling potentiometry"
Phys. Rev. B 62 (13), 8596-8599 (2000).

C. Hordequin, D. Ristoiu, L. Ranno et J. Pierre
"On the cross over from half-metal to normal ferromagnet in NiMnSb"
Europhys. J. B 16, 287-293 (2000).

R. Kalinowski, C. Meyer, A. Wawro et L. T. Baczewski
"Magnetic anisotropy in MBE-grown epitaxial gadolinium ultra-thin films"
Thin Solid Films 367, 189 (2000).

S. Pignard, G. Goglio, I. Huynen, A. Radulescu et L. Piraux
"Ferromagnetic resonance in submicron metallic wires"
IEEE Trans. Magn. 36 (5), 3482 (2000).

S. Pignard, G. Goglio, L. Piraux, S. Dubois, A. Déclémy et J. L. Duvail
"Study of the magnetization reversal in individual nickel nanowires"
J. Appl. Phys. 87 (2), 824 (2000).

D. Ristoiu, J. P. Nozières et L. Ranno
"Epitaxial NiMnSb thin films prepared by facing targets sputtering"
J. Magn. Magn. Mater. 219, 97-103 (2000).