K. H. Gundlach, Theory of metal???insulator???metal tunneling for a simple two???band model, Journal of Applied Physics, vol.44, issue.11, p.5005, 1973.
DOI : 10.1063/1.1662078

P. Rottländer, M. Hehn, and A. Schuhl, Determining the interfacial barrier height and its relation to tunnel magnetoresistance, Physical Review B, vol.65, issue.5, p.54422, 2002.
DOI : 10.1103/PhysRevB.65.054422

J. J. Akerman, Criteria for ferromagnetic???insulator???ferromagnetic tunneling, Journal of Magnetism and Magnetic Materials, vol.240, issue.1-3, p.86, 2002.
DOI : 10.1016/S0304-8853(01)00712-0

R. Stratton, Volt-current characteristics for tunneling through insulating films, Journal of Physics and Chemistry of Solids, vol.23, issue.9, p.1177, 1962.
DOI : 10.1016/0022-3697(62)90165-8

R. Meservey and P. M. Tedrow, Spin-polarized electron tunneling, Physics Reports, vol.238, issue.4, p.173, 1994.
DOI : 10.1016/0370-1573(94)90105-8

D. J. Monsma and S. S. Parkin, Spin polarization of tunneling current from ferromagnet/Al2O3 interfaces using copper-doped aluminum superconducting films, Applied Physics Letters, vol.77, issue.5, p.720, 2000.
DOI : 10.1063/1.127097

M. Tondra, Micromagnetic design of spin dependent tunnel junctions for optimized sensing performance, Journal of Applied Physics, vol.87, issue.9, p.4679, 2000.
DOI : 10.1063/1.373128

M. R. Mccartney, Origin of Magnetization Decay in Spin-Dependent Tunnel Junctions, Science, vol.286, issue.5443, p.1337, 1999.
DOI : 10.1126/science.286.5443.1337

L. Thomas, M. G. Samant, and S. S. Parkin, Domain-Wall Induced Coupling between Ferromagnetic Layers, Physical Review Letters, vol.84, issue.8, p.1816, 2000.
DOI : 10.1103/PhysRevLett.84.1816

L. Thomas, Oscillatory Decay of Magnetization Induced by Domain-Wall Stray Fields, Physical Review Letters, vol.84, issue.15, p.3462, 2000.
DOI : 10.1103/PhysRevLett.84.3462

J. Nogués and I. K. Schuller, Exchange bias, Journal of Magnetism and Magnetic Materials, vol.192, issue.2, p.203, 1998.
DOI : 10.1016/S0304-8853(98)00266-2

A. E. Berkowitz and K. Takano, Exchange anisotropy ??? a review, Journal of Magnetism and Magnetic Materials, vol.200, issue.1-3, p.552, 1999.
DOI : 10.1016/S0304-8853(99)00453-9

D. V. Berkov and N. L. Gorn, Quasistatic remagnetization processes in two-dimensional systems with random on-site anisotropy and dipolar interaction: Numerical simulations, Physical Review B, vol.57, issue.22, p.14332, 1998.
DOI : 10.1103/PhysRevB.57.14332

K. Moon, R. E. Fontana, and S. S. Parkin, Exchange-biased magnetic tunnel junctions: Dependence of offset field on junction width, Applied Physics Letters, vol.74, issue.24, p.3690, 1999.
DOI : 10.1063/1.123222

B. D. Schrag, N??el ???orange-peel??? coupling in magnetic tunneling junction devices, Applied Physics Letters, vol.77, issue.15, p.2373, 2000.
DOI : 10.1063/1.1315633

M. Bowen, Large magnetoresistance in Fe/MgO/FeCo(001) epitaxial tunnel junctions on GaAs(001), Applied Physics Letters, vol.79, issue.11, p.1655, 2001.
DOI : 10.1063/1.1404125

R. J. Shang, J. Nowak, and J. S. Moodera, Temperature dependence of magnetoresistance and surface magnetization in ferromagnetic tunnel junctions, Physical Review B, vol.58, issue.6, p.2917, 1998.
DOI : 10.1103/PhysRevB.58.R2917

R. K. Hagler and G. Bayreuther, Temperature dependence of tunnel magnetoresistance, Journal of Applied Physics, vol.89, issue.11, p.7570, 2001.
DOI : 10.1063/1.1359229

M. Pakala, Y. Huai, G. Anderson, and L. Miloslavsky, Effect of underlayer roughness, grain size, and crystal texture on exchange coupled IrMn/CoFe thin films, Journal of Applied Physics, vol.87, issue.9, p.6653, 2000.
DOI : 10.1063/1.372800

D. J. Monsma, R. Vlutters, and J. C. Lodder, Room Temperature-Operating Spin-Valve Transistors Formed by Vacuum Bonding, Science, vol.281, issue.5375, p.407, 1998.
DOI : 10.1126/science.281.5375.407
URL : http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.608.1054

M. Hehn, F. Montainge, and A. Schuhl, Hot-electron three-terminal devices based on magnetic tunnel junction stacks, Physical Review B, vol.66, issue.14, p.144411, 2002.
DOI : 10.1103/PhysRevB.66.144411

P. Rottländer, M. Hehn, O. Lenoble, and A. Schuhl, Tantalum oxide as an alternative low height tunnel barrier in magnetic junctions, Applied Physics Letters, vol.78, issue.21, p.3274, 2001.
DOI : 10.1063/1.1374223

R. Vlutters, Hot-electron transport through Ni80Fe20 in a spin-valve transistor, Journal of Applied Physics, vol.89, issue.11, p.7305, 2001.
DOI : 10.1063/1.1357853

A. Annexe, Les conditions d'´ elaboration L'objectif de cettepremì ere annexe est de décrire les conditions dans les quelles leséchantillonsétudiésleséchantillonsleséchantillonsétudiés au cours de cette thèse ontétéélaborésontétéontétéélaborés. La premì ere partie contient un descriptif des protocoles suivis avant le dépôt des couches minces pour la préparation de chaque type de substrats