P. Tartaj, M. Morales, P. Del, S. Veintemillas-verdaguer, T. González-carreño et al., The preparation of magnetic nanoparticles for applications in biomedicine, Journal of Physics D: Applied Physics, vol.36, issue.13
DOI : 10.1088/0022-3727/36/13/202

D. Appl and . Phys, , pp.182-197, 2003.

J. B. Haun, T. J. Yoon, H. Lee, and R. Weissleder, Magnetic nanoparticle biosensors, Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology, vol.359, issue.3, pp.291-304, 2010.
DOI : 10.1056/NEJMoa0800668

N. A. Frey, S. Peng, K. Cheng, and S. Sun, Magnetic nanoparticles: synthesis, functionalization, and applications in bioimaging and magnetic energy storage, Chemical Society Reviews, vol.91, issue.291
DOI : 10.1557/mrs2001.254

, Soc. Rev, vol.38, p.2532, 2009.

E. A. Schultz-sikma, H. M. Joshi, M. Qing, K. W. Macrenaris, A. L. Eckermann et al., Probing the Chemical Stability of Mixed Ferrites: Implications for Magnetic Resonance Contrast Agent Design, Chemistry of Materials, vol.23, issue.10, pp.2657-2664, 2011.
DOI : 10.1021/cm200509g

C. Sun, J. Lee, and M. Zhang, Magnetic nanoparticles in MR imaging and drug delivery

, Adv. Drug Deliv. Rev, vol.60, pp.1252-1265, 2008.

P. Guardia and N. P-re, Controlled Synthesis of Iron Oxide Nanoparticles over a Wide Size Range, Langmuir, vol.26, issue.8, pp.5843-5847, 2010.
DOI : 10.1021/la903767e

D. Maity, S. N. Kale, R. Kaul-ghanekar, J. Xue, and J. Ding, Studies of magnetite nanoparticles synthesized by thermal decomposition of iron (III) acetylacetonate in tri(ethylene glycol), Journal of Magnetism and Magnetic Materials, vol.321, issue.19, pp.3093-3098, 2009.
DOI : 10.1016/j.jmmm.2009.05.020

N. D. Thorat, V. M. Khot, A. B. Salunkhe, A. I. Prasad, R. S. Ningthoujam et al., Surface functionalized LSMO nanoparticles with improved colloidal stability for hyperthermia applications, Journal of Physics D: Applied Physics, vol.46, issue.10, p.105003, 2013.
DOI : 10.1088/0022-3727/46/10/105003

A. Vergés, M. Costo, R. Roca, A. G. Marco, J. F. Goya et al., Uniform and water stable magnetite nanoparticles with diameters around the monodomain???multidomain limit, Journal of Physics D: Applied Physics, vol.41, issue.13, p.134003, 2008.
DOI : 10.1088/0022-3727/41/13/134003

L. Shi, R. Zhao, and T. C. Chong, Developments in Data Storage, pp.277-296, 2011.

M. Faraji, Y. Yamini, and M. Rezaee, Magnetic nanoparticles: Synthesis, stabilization, functionalization, characterization, and applications, Journal of the Iranian Chemical Society, vol.42, issue.1199, pp.1-37, 2010.
DOI : 10.1021/ja0517365

R. H. Kodama and A. E. Berkowitz, Atomic-scale magnetic modeling of oxide nanoparticles, Physical Review B, vol.3, issue.9, pp.6321-6336, 1999.
DOI : 10.1103/PhysRevB.3.1039

J. M. Coey, Noncollinear Spin Arrangement in Ultrafine Ferrimagnetic Crystallites, Physical Review Letters, vol.17, issue.17, pp.1140-1142, 1971.
DOI : 10.1139/p70-356

K. Haneda and A. H. Morrish, Noncollinear magnetic structure of CoFe 2 O 4 small particles

, J. Appl. Phys, vol.63, p.4258, 1988.

M. P. Morales, C. J. Serna, F. Bødker, and S. Mørup, Spin canting due to structural disorder in maghemite, Journal of Physics: Condensed Matter, vol.9, issue.25, pp.5461-5467, 1999.
DOI : 10.1088/0953-8984/9/25/013

D. Peddis, N. Yaacoub, M. Ferretti, A. Martinelli, and G. Piccaluga, Nanoparticles, The Journal of Physical Chemistry B, vol.112, issue.29, pp.8507-8513, 2008.
DOI : 10.1021/jp8016634

URL : https://hal.archives-ouvertes.fr/hal-01492683

B. Martínez, X. Obradors, L. Balcells, A. Rouanet, and C. Monty, Nanoparticles, Physical Review Letters, vol.67, issue.34, pp.181-184, 1998.
DOI : 10.1103/PhysRevLett.67.3602

J. E. Lima, A. L. Brandl, A. D. Arelaro, and G. Goya, Spin disorder and magnetic anisotropy in Fe3O4 nanoparticles, Journal of Applied Physics, vol.2, issue.8, pp.83908-83910, 2006.
DOI : 10.1103/PhysRevB.56.14551

H. J. Fan, U. Gosele, and M. Zacharias, Formation of Nanotubes and Hollow Nanoparticles Based on Kirkendall and Diffusion Processes: A Review, Small, vol.17, issue.10, pp.1660-1671, 2007.
DOI : 10.1360/cjcp2006.19(6).543.6

A. Cabot, V. F. Puntes, E. Shevchenko, Y. Yin, M. A. Marcus et al., Vacancy Coalescence during Oxidation of Iron Nanoparticles. J. Am

, Chem. Soc, vol.129, pp.10358-10360, 2007.

Y. Yin, C. K. Erdonmez, A. Cabot, S. Hughes, and A. P. Alivisatos, Colloidal Synthesis of Hollow Cobalt Sulfide Nanocrystals, Advanced Functional Materials, vol.124, issue.11, pp.1389-1399, 2006.
DOI : 10.1002/adfm.200600256

Y. Yin, R. M. Rioux, C. K. Erdnmez, S. Hughes, G. A. Somorjai et al., Formation of Hollow Nanocrystals Through the, Nanoscale Kirkendall Effect. Science, vol.304, pp.711-714, 2004.

A. Cabot, R. K. Smith, Y. Yin, H. Zheng, B. M. Reinhard et al., Sulfidation of Cadmium at the Nanoscale, ACS Nano, vol.2, issue.7, pp.1452-1458, 2008.
DOI : 10.1021/nn800270m

G. G. Lin and J. G. Scott, The Role of Frozen Spins in the Exchange Anisotropy of Core? Shell Fe@Fe 3 O 4 Nanoparticles, J. Phys. Chem. C, vol.100, pp.130-134, 2012.

Q. K. Ong, A. Wei, and X. M. Lin, Exchange bias in Fe/Fe 3 O 4 core-shell magnetic nanoparticles mediated by frozen interfacial spins, Phys. Rev. B, vol.80, pp.1-6, 2009.

G. H. Jaffari, A. Ceylan, C. Ni, and S. I. Shah, Enhancement of surface spin disorder in hollow NiFe 2 O 4 nanoparticles, J. Appl. Phys, vol.107, 2010.

H. Khurshid, W. Li, M. H. Phan, P. Mukherjee, G. C. Hadjipanayis et al., Surface spin disorder and exchange-bias in hollow maghemite nanoparticles, Applied Physics Letters, vol.8, issue.2
DOI : 10.1063/1.3119632

, Lett, vol.101, pp.8-13, 2012.

H. Khurshid, M. H. Phan, P. Mukherjee, and H. Srikanth, Tuning e change bias in Fe, p.112

, Fe 2 O 3 core-shell nanoparticles: Impacts of interface and surface spins, Appl. Phys. Lett, vol.104, pp.2012-2017, 2014.

H. Khurshid, W. Li, M. H. Phan, P. Mukherjee, G. C. Hadjipanayis et al., Surface spin disorder and exchange-bias in hollow maghemite nanoparticles, Applied Physics Letters, vol.8, issue.2
DOI : 10.1063/1.3119632

, Lett, vol.101, pp.8-13, 2012.

H. Khurshid, P. Lampen-kelley, O. Iglesias, J. Alonso, M. H. Phan et al., Spin-glass-like freezing of inner and outer surface layers in hollow ??-Fe2O3 nanoparticles, Scientific Reports, vol.22, p.15054, 2015.
DOI : 10.1088/0957-4484/22/26/265605

URL : https://hal.archives-ouvertes.fr/hal-01228094

A. Cabot, A. P. Alivisatos, V. F. Puntes, and L. Balcells, Magnetic domains and surface effects in hollow maghemite nanoparticles, Physical Review B, vol.79, issue.9, p.94419, 2009.
DOI : 10.1021/cm991018f

O. Iglesias, A. Labarta, and X. Batlle, Exchange Bias Phenomenology and Models of Core/Shell Nanoparticles, ChemInform, vol.38, issue.8, pp.2761-2780, 2008.
DOI : 10.1002/chin.200708215

L. Berger, Y. Labaye, M. Tamine, and J. M. Coey, Ferromagnetic nanoparticles with strong surface anisotropy: Spin structures and magnetization processes, Physical Review B, vol.272, issue.276, pp.1-10, 2008.
DOI : 10.1063/1.1845891

Y. Labaye, L. Berger, and J. M. Coey,

, J. Appl. Phys, vol.91, pp.5341-5346, 2002.

G. H. Jaffari, A. Ceylan, H. P. Bui, T. P. Beebe, S. Ozcan et al., nanoparticles, Journal of Physics: Condensed Matter, vol.24, issue.33, p.336004, 2012.
DOI : 10.1088/0953-8984/24/33/336004

A. J. Fabiano and J. Qiu, Post-stereotactic radiosurgery brain metastases: A review, J. Neurosurg. Sci, vol.59, pp.157-167, 2015.

S. Blundell, Magnetism in Condensed Matter, 2001.

S. Bedanta, W. Kleemann, and . Supermagnetism, Supermagnetism, Journal of Physics D: Applied Physics, vol.42, issue.1, p.13001, 2009.
DOI : 10.1088/0022-3727/42/1/013001

E. C. Stoner and E. P. Wohlfarth, A Mechanism of Magnetic Hysteresis in Heterogeneous Alloys, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol.240, issue.826, pp.599-642, 1948.
DOI : 10.1098/rsta.1948.0007

M. J. Dekkers, Environmental magnetism: an introduction, Geologie en Mijnbouw (Geology and Mining), vol.76, issue.1/2, pp.163-182, 1997.
DOI : 10.1023/A:1003122305503

D. Farrelly, Advances in Chemical Physics, Journal of the American Chemical Society, vol.141, issue.131, 2009.

J. L. Dormann, D. Fiorani, and E. Tronc, Magnetic Relaxation in Fine-Particle Systems, Adv. Chem. Phys, vol.1, issue.144, p.293, 1997.
DOI : 10.1007/978-94-009-5697-1

E. Tronc, P. Prene, J. P. Jolivet, F. Ora-io, F. Lucari et al., Magnetic behaviour of ??-Fe2O3 nanoparticles by m??ssbauer spectroscopy and magnetic measurements, Hyperfine Interactions, vol.15, issue.1, pp.129-148, 1995.
DOI : 10.1103/PhysRevB.46.11657

D. Peddis, Nanostructured Magnets Synthesis and Characterization of CoFe 2 O 4 nanoparticles, 2006.

S. Foner, Versatile and Sensitive Vibrating-Sample Magnetometer*. The review of scientific instruments 30, pp.548-557, 1959.

S. Mørup, E. Brok, and C. Frandsen, Spin Structures in Magnetic Nanoparticles, Journal of Nanomaterials, vol.63, issue.18, pp.1-8, 2013.
DOI : 10.1088/0022-3719/20/10/005

A. H. Lu, E. L. Salabas, and F. Schüth, Magnetic Nanoparticles: Synthesis, Protection, Functionalization, and Application, Angewandte Chemie International Edition, vol.92, issue.8, pp.1222-1244, 2007.
DOI : 10.3181/00379727-158-40158

R. H. Kodama, Magnetic nanoparticles, Journal of Magnetism and Magnetic Materials, vol.200, issue.1-3, pp.359-372, 1999.
DOI : 10.1016/S0304-8853(99)00347-9

H. Kachkachi and H. Mahboub, Surface anisotropy in nanomagnets : transverse or N el, J

, Magn. Magn. Mater, vol.278, pp.334-341, 2004.

V. Skumryev, S. Stoyanov, and Y. Zhang, Beating the superparamagnetic limit with exchange bias, Nature, vol.27, issue.6942, pp.19-22, 2003.
DOI : 10.1103/PhysRevLett.27.1140

J. Nogués, J. Sort, V. Langlais, V. Skumryev, S. Suriñach et al., Exchange bias in nanostructures, Physics Reports, vol.422, issue.3, pp.65-117, 2005.
DOI : 10.1016/j.physrep.2005.08.004

A. E. Berkowitz and K. Takano, Exchange anisotropy ??? a review, Journal of Magnetism and Magnetic Materials, vol.200, issue.1-3, pp.552-570, 1999.
DOI : 10.1016/S0304-8853(99)00453-9

J. Nogués and I. K. Schuller, Exchange bias, Journal of Magnetism and Magnetic Materials, vol.192, issue.2, pp.203-232, 1999.
DOI : 10.1016/S0304-8853(98)00266-2

M. Kiwi, Exchange bias theory, Journal of Magnetism and Magnetic Materials, vol.234, issue.3, pp.584-595, 2001.
DOI : 10.1016/S0304-8853(01)00421-8

D. Peddis, P. E. Jönsson, S. Laureti, and G. Varvaro, Magnetic Interactions, pp.129-188, 2014.
DOI : 10.1016/B978-0-08-098353-0.00004-X

J. M. Grenèche and . Interfaces, Interfaces, Surfaces and Grain Boundaries in Nanophase Materials Evidenced by M??ssbauer Spectrometry, Materials Science Forum, vol.307, pp.159-166, 1999.
DOI : 10.4028/www.scientific.net/MSF.307.159

R. L. Mössbauer, Kernresonanzfluoreszenz von Gammastrahlung in 191 Ir. Zeitschrift für Physik, pp.124-143, 1958.

R. Mössbauer, Kernresonan absorption von ?-Strahlung in 191 Ir, 1959.

R. L. Mössbauer, Recoilless Nuclear Resonance Absorption, Annual Review of Nuclear Science, vol.12, issue.1, pp.123-152, 1962.
DOI : 10.1146/annurev.ns.12.120162.001011

J. Chappert, High Field Mössbauer Spectroscopy, J. Phys. Colloq, vol.35, pp.6-71, 1974.

J. Chappert, J. Teillet, and F. Varret, Recent developments in high field M??ssbauer spectroscopy, Journal of Magnetism and Magnetic Materials, vol.11, issue.1-3, pp.200-207, 1979.
DOI : 10.1016/0304-8853(79)90265-8

J. M. Coey, Noncollinear Spin Arrangement in Ultrafine Ferrimagnetic Crystallites, Physical Review Letters, vol.17, issue.17, pp.1140-1142, 1971.
DOI : 10.1139/p70-356

J. M. Coey and P. W. Readman, New Spin Structure in an Amorphous Ferric Gel, Nature, vol.27, issue.5434, 1973.
DOI : 10.1038/246476a0

J. M. Coey, J. Chappert, J. P. Rebouillat, and T. S. Wang, Magnetic Structure of an Amorphous Rare-Earth Transition-Metal Alloy, Physical Review Letters, vol.246, issue.17, p.36, 1976.
DOI : 10.1038/246476a0

J. W. Niemantsverdriet and . Spectroscopy, Spectroscopy in Catalysis, 2007.

J. L. Dormann and D. Fiorani, Magnetic properties of fine particles. ( msterdam, 1992.

D. Peddis, N. Yaacoub, M. Ferretti, A. Martinelli, G. Piccaluga et al., nanoparticles, Journal of Physics: Condensed Matter, vol.23, issue.42, p.426004, 2011.
DOI : 10.1088/0953-8984/23/42/426004

URL : https://hal.archives-ouvertes.fr/hal-01492683

T. J. Daou, J. Greneche, S. J. Lee, S. C. Lee, C. Lefevre et al., Spin Canting of Maghemite Studied by NMR and In-Field Mössbauer Spectrometry, J

. Phys and . Chem, , pp.8794-8799, 2010.

C. P. Bean, J. D. Livingston, and . Superparamagnetism, Superparamagnetism, Journal of Applied Physics, vol.7, issue.4, p.120, 1959.
DOI : 10.1080/14786435808244578

G. F. Goya, T. S. Er-u, F. C. Fonseca, and M. P. Morales, Static and dynamic magnetic properties of spherical magnetite nanoparticles, Journal of Applied Physics, vol.84, issue.5, p.3520, 2003.
DOI : 10.1016/0304-8853(94)90683-1

F. C. Fonseca, G. F. Goya, R. F. Jardim, R. Muccillo, N. L. Carreño et al., Physical Review B, vol.221, issue.230, p.104406, 2002.
DOI : 10.1016/S0304-8853(00)00441-8

T. Jonsson, J. Mattsson, P. Nordblad, and P. Svedlindh, Energy barrier distribution of a noninteracting nano-sized magnetic particle system, Journal of Magnetism and Magnetic Materials, vol.168, issue.3, pp.269-277, 1997.
DOI : 10.1016/S0304-8853(96)00710-X

M. E. Lopez-herrera, J. M. Greneche, and F. Varret, Analysis of the M??ssbauer quadrupole spectra of some amorphous fluorides, Physical Review B, vol.35, issue.18, pp.4944-4948, 1983.
DOI : 10.1016/0038-1098(80)90766-8

G. Ferey, F. Varret, and J. M. Coey, : a non-crystalline magnet with antiferromagnetic interactions, Journal of Physics C: Solid State Physics, vol.12, issue.13, pp.531-537, 1979.
DOI : 10.1088/0022-3719/12/13/009

H. Khurshid, W. Li, V. Tzitzios, and G. C. Hadjipanayis, Chemically synthesized hollow nanostructures in iron oxides, Nanotechnology, vol.22, issue.26, p.265605, 2011.
DOI : 10.1088/0957-4484/22/26/265605

C. M. Hurd, Varieties of magnetic order in solids, Contemporary Physics, vol.20, issue.5, pp.469-493, 1982.
DOI : 10.1016/0304-8853(80)90528-4

L. Machala, R. Zboril, and A. Gedanken, Amorphous Iron(III) Oxide ??? A Review, ChemInform, vol.111, issue.28, pp.4003-4018, 2007.
DOI : 10.1002/chin.200728192

J. M. Coey and P. W. Readman, Characterisation and magnetic properties of natural ferric gel, Earth and Planetary Science Letters, vol.21, issue.1, pp.45-51, 1973.
DOI : 10.1016/0012-821X(73)90224-0

J. L. Dormann, D. Fiorani, and E. Tronc, Magnetic Relaxation in Fine-Particle Systems, Adv. Chem. Phys, vol.1, issue.144, p.293, 1997.
DOI : 10.1007/978-94-009-5697-1

S. Belaïd, S. Laurent, M. Vermeech, L. Vander-elst, D. Perez-morga et al., A new approach to follow the formation of iron oxide nanoparticles synthesized by thermal decomposition, Nanotechnology, vol.24, issue.5, p.55705, 2013.
DOI : 10.1088/0957-4484/24/5/055705

A. Cabot, V. F. Puntes, E. Shevchenko, Y. Yin, L. Balcells et al., Vacancy Coalescence during Oxidation of Iron Nanoparticles, Journal of the American Chemical Society, vol.129, issue.34
DOI : 10.1021/ja072574a

, Chem. Soc, vol.129, pp.10358-10360, 2007.

J. I. Gittleman, B. Abeles, and S. Bozowski, films, Physical Review B, vol.7, issue.9, pp.3891-3897, 1974.
DOI : 10.1103/PhysRevB.7.1103

D. Peddis, C. Cannas, G. Piccaluga, E. Agostinelli, and D. Fiorani, nanoparticles, Nanotechnology, vol.21, issue.12, p.125705, 2010.
DOI : 10.1088/0957-4484/21/12/125705

URL : https://hal.archives-ouvertes.fr/hal-01492683

Y. Labaye, O. Crisan, L. Berger, J. M. Greneche, and J. M. Coey, Surface anisotropy in ferromagnetic nanoparticles, Journal of Applied Physics, vol.220, issue.10, 2002.
DOI : 10.1126/science.220.4598.671

URL : https://hal.archives-ouvertes.fr/hal-02127519

S. Ozawa, Y. Sasajima, and D. W. Heermann, Monte Carlo simulations of film growth, Thin Solid Films, vol.272, issue.2, pp.172-183, 1996.
DOI : 10.1016/0040-6090(95)06944-5

S. Kirkpatrick, Optimization by simulated annealing: Quantitative studies, Journal of Statistical Physics, vol.21, issue.5-6, pp.975-986, 1984.
DOI : 10.1007/BF01009452

J. Restrepo, Y. Labaye, and J. M. Greneche, Surface anisotropy in maghemite nanoparticles, Physica B: Condensed Matter, vol.384, issue.1-2, pp.221-223, 2006.
DOI : 10.1016/j.physb.2006.05.267

A. U. Gehring, H. Fischer, M. Louvel, K. Kunze, and P. G. Weidler, High temperature stability of natural maghemite: a magnetic and spectroscopic study, Geophysical Journal International, vol.106, issue.3, pp.1361-1371, 2009.
DOI : 10.2138/am-2004-5-601

D. A. Garanin and H. Kachkachi, Surface Contribution to the Anisotropy of Magnetic Nanoparticles, Physical Review Letters, vol.15, issue.6, p.65504, 2003.
DOI : 10.1103/PhysRevB.49.15084

I. Chamritski and G. Burns, Infrared- and Raman-Active Phonons of Magnetite, Maghemite, and Hematite:?? A Computer Simulation and Spectroscopic Study, The Journal of Physical Chemistry B, vol.109, issue.11
DOI : 10.1021/jp048748h

, Chem. B, vol.109, pp.4965-4968, 2005.

P. J. Mitchell and D. Fincham, Shell model simulations by adiabatic dynamics, Journal of Physics: Condensed Matter, vol.5, issue.8, pp.1031-1038, 1993.
DOI : 10.1088/0953-8984/5/8/006

G. V. Lewis and C. R. Catlow, Potential models for ionic oxides, Journal of Physics C: Solid State Physics, vol.18, issue.6, pp.1149-1161, 1985.
DOI : 10.1088/0022-3719/18/6/010

H. Donnerberg, M. Exner, and C. R. Catlow, Physical Review B, vol.88, issue.1, pp.14-19, 1993.
DOI : 10.1002/bbpc.19840881006

S. M. Woodley, P. D. Battle, J. D. Gale, C. , and C. R. , The prediction of inorganic crystal structures using a genetic algorithm and energy minimisation, Physical Chemistry Chemical Physics, vol.1, issue.10, pp.2535-2542, 1999.
DOI : 10.1039/a901227c

D. J. Hardy, Z. Whu, J. C. Phillips, J. I. Stone, R. D. Skeel et al., Multilevel Summation Method for Electrostatic Force Evaluation, Journal of Chemical Theory and Computation, vol.11, issue.2, pp.766-779, 2015.
DOI : 10.1021/ct5009075

F. Sayed, Y. Labaye, R. Sayed-hassan, F. El-haj-hassan, N. Yaacoub et al., Size and thickness effect on magnetic structures of maghemite hollow magnetic nanoparticles, Journal of Nanoparticle Research, vol.14, issue.3, p.279, 2016.
DOI : 10.1021/cm0111074

URL : https://hal.archives-ouvertes.fr/hal-02269326

S. Bose, A. R. Bhattacharyya, P. V. Kodgire, A. R. Kulkarni, and A. Misra, Specific Interactions Induced Dispersion and Confinement of Multi-Walled Carbon Nanotubes in Co-continuous Polymer Blends, J. Nanosci. Nanotechnol, vol.8, pp.1867-1879, 2008.

W. H. Meiklejohn and C. Bean, New Magnetic Anisotropy, Physical Review, vol.22, issue.3, pp.904-913, 1957.
DOI : 10.1063/1.1739881

R. H. Kodama, A. E. Berkowitz, J. Mcniff, E. J. Foner, and S. , Nanoparticles, Surface Spin Disorder in NiFe 2 O 4 Nanoparticles, pp.394-397, 1996.
DOI : 10.1063/1.332706

S. Chandra, A. Biswas, S. Datta, B. Ghosh, K. Raychaudhuri et al., nanowires, Nanotechnology, vol.24, issue.50, p.505712, 2013.
DOI : 10.1088/0957-4484/24/50/505712

B. Martínez, X. Obradors, L. Balcells, A. Rouanet, and C. Monty, Nanoparticles, Physical Review Letters, vol.67, issue.34, pp.181-184, 1998.
DOI : 10.1103/PhysRevLett.67.3602

T. N. Shendruk, R. D. Desautels, B. W. Southern, and J. Van-lierop, nanoparticle dispersions, Nanotechnology, vol.18, issue.45, p.455704, 2007.
DOI : 10.1088/0957-4484/18/45/455704

K. N. Trohidou, M. Vasilakaki, D. Bianco, L. Fiorani, D. Testa et al., Exchange bias in a magnetic ordered/disordered nanoparticle system: A Monte Carlo simulation study, Journal of Magnetism and Magnetic Materials, vol.316, issue.2, pp.82-85, 2007.
DOI : 10.1016/j.jmmm.2007.02.035

E. Eftaxias and K. N. Trohidou, Numerical study of the exchange bias effects in magnetic nanoparticles with core/shell morphology, Physical Review B, vol.71, issue.13, pp.1-6, 2005.
DOI : 10.1103/PhysRevB.63.184416

X. Sun, N. Frey-huls, A. Sigdel, and S. Sun, Nanoparticles, Nano Letters, vol.12, issue.1, pp.246-251, 2012.
DOI : 10.1021/nl2034514

URL : https://hal.archives-ouvertes.fr/hal-01320702

H. Khurshid, W. Li, M. H. Phan, P. Mukherjee, G. C. Hadjipanayis et al., Surface spin disorder and exchange-bias in hollow maghemite nanoparticles, Applied Physics Letters, vol.8, issue.2
DOI : 10.1063/1.3119632

, Lett, vol.101, pp.0-5, 2012.

K. Simeonidis, O. Iglesias, A. Cabot, M. Angelakeris, S. Mourdikoudis et al., Morphology influence on nanoscale magnetism of Co nanoparticles: Experimental and theoretical aspects of exchange bias, Physical Review B, vol.8, issue.14, p.144430, 2011.
DOI : 10.1103/PhysRevB.70.184432

J. I. Gittleman, B. Abeles, and S. Bozowski, films, Physical Review B, vol.7, issue.9, pp.3891-3897, 1974.
DOI : 10.1103/PhysRevB.7.1103

M. F. Hansen and S. Mørup, Estimation of blocking temperatures from ZFC/FC curves, Journal of Magnetism and Magnetic Materials, vol.203, issue.1-3
DOI : 10.1016/S0304-8853(99)00238-3

, Magn. Magn. Mater, vol.203, pp.214-216, 1999.

, Annex Annex Bibliography

W. Bragg, The Structure of Magnetite and the Spinels, Nature, vol.95, issue.2386, pp.561-561, 1915.
DOI : 10.1038/095561a0

S. Nishikawa, Structure of Some Crystals of Spinel Group, Proc. Tokyo Math. Soc. 2nd Ser, pp.199-209, 1915.

R. Grau-crespo, A. Y. Baitai, I. Saadoune, and N. H. De-leeuw, (maghemite): a theoretical investigation, Journal of Physics: Condensed Matter, vol.22, issue.25, p.255401, 2010.
DOI : 10.1088/0953-8984/22/25/255401

M. P. Morales, C. Pecharroman, T. G. Carreñ, and C. J. Serna, Structural Characteristics of Uniform ??-Fe2O3 Particles with Different Axial (Length/Width) Ratios, Journal of Solid State Chemistry, vol.108, issue.1, pp.158-163, 1994.
DOI : 10.1006/jssc.1994.1024

A. N. Shmakov, G. N. Krvukova, S. V. Tsvbulya, A. L. Chuvilin, and L. P. Solovyeva, : Synchrotron X-ray Powder Diffraction and High-Resolution Electron Microscopy Studies, Journal of Applied Crystallography, vol.28, issue.2, pp.141-145, 1995.
DOI : 10.1107/S0021889894010113

Q. K. Ong, X. Lin, and A. Wei, Nanoparticles, The Journal of Physical Chemistry C, vol.115, issue.6, pp.2665-2672, 2011.
DOI : 10.1021/jp110716g

URL : https://hal.archives-ouvertes.fr/hal-01682224

G. H. Jaffari, A. Ceylan, C. Ni, and S. I. Shah, Enhancement of surface spin disorder in hollow NiFe2O4 nanoparticles, Journal of Applied Physics, vol.171, issue.1, p.13910, 2010.
DOI : 10.1016/j.biomaterials.2007.08.050

H. Khurshid, Core/shell structured iron/iron-oxide nanoparticles as excellent MRI contrast enhancement agents, Journal of Magnetism and Magnetic Materials, vol.331, pp.17-20, 2013.
DOI : 10.1016/j.jmmm.2012.10.049

H. Khurshid, Surface spin disorder and exchange-bias in hollow maghemite nanoparticles, Applied Physics Letters, vol.8, issue.2, p.22403, 2012.
DOI : 10.1063/1.3119632

H. Khurshid, W. Li, V. Tzitzios, and G. C. Hadjipanayis, Chemically synthesized hollow nanostructures in iron oxides, Nanotechnology, vol.22, issue.26, p.265605, 2011.
DOI : 10.1088/0957-4484/22/26/265605

A. Cabot, Vacancy Coalescence during Oxidation of Iron Nanoparticles, Journal of the American Chemical Society, vol.129, issue.34, pp.10358-10360, 2007.
DOI : 10.1021/ja072574a

R. Singh, V. Misra, and R. P. Singh, Synthesis, characterization and role of zero-valent iron nanoparticle in removal of hexavalent chromium from chromium-spiked soil, Journal of Nanoparticle Research, vol.21, issue.9, pp.4063-4073, 2011.
DOI : 10.1021/es00160a010

R. L. Fagaly, SQUID Instruments and Applications, Rev. Sci. Instrum, 2005.