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Optical Spectroscopy on Magnetically Doped Semiconductor Nanoparticles

  • Lars Schneider
  • Gerd Bacher
Chapter
Part of the NanoScience and Technology book series (NANO)

Abstract

Semiconductor nanoparticles doped with magnetic ions represent an exciting class of materials with unique optical, electronic, and magnetic properties and potential applications in the field of spintronics. A key feature required is the exchange interaction between magnetic ions and charge carriers, which finally controls the magneto-optical response of these materials. In this contribution, some recent advances for two classes of magnetically doped nanoparticles, namely, ZnO doped with Cr and Co, respectively, and CdSe doped with Mn, are summarized. We found that chromium is incorporated as Cr\(^{3+}\) in ZnO. With increasing Cr concentration, the quantum efficiency is being reduced while the magnetic properties observed can be attributed to a phase separation between ZnO and ZnCr\(_{2}\)O\(_{4}\). In contrast, cobalt apparently exists in the Co\(^{2+}\) configuration in the nanocrystals as demonstrated via optical spectroscopy. No enhanced magneto-optical properties have been obtained for both classes of magnetically doped ZnO nanoparticles. This is completely different in case of Mn-doped CdSe nanocrystals. A giant Zeeman effect is found as a consequence of a pronounced spd exchange interaction. The strong 3D carrier confinement finally results in a significantly enhanced exchange field leading to the observation of optically induced magnetism up to room temperature.

Keywords

Exchange Field CdSe Nanoparticles CdSe Nanocrystals Recombination Lifetime Bright Exciton 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

The authors are indebted to Wei Jin, Ruzica Djenadic and Markus Winterer for preparing the Cr\(^{3+}\)- and Co\(^{2+}\)-doped ZnO nanoparticles and performing XRD and XANES measurements and Mehmet Acet for SQUID investigations of ZnO:Cr\(^{3+}\) nanoparticles. The preparation of excellent CdSe:Mn\(^{2+}\) nanocrystals by Remi Beaulac, Paul I Archer, and Daniel R. Gamelin, and the very fruitful collaboration in that field is gratefully acknowledged. We thank Rachel Fainblat-Padua for a critical reading of the manuscript and the German Research Foundation for financial support within the SFB 445—Nanoparticles from the gas phase.

References

  1. 1.
    T. Hayashi, M. Tanaka, K. Seto, T. Nishinaga, K. Ando, III-V based magnetic (GaMnAs)/nonmagnetic(AlAs) semiconductor superlattices. Appl. Phys. Lett. 71, 1825 (1997)ADSCrossRefGoogle Scholar
  2. 2.
    S. Koshihara, A. Oiwa, M. Hirasawa, S. Katsumoto, Y. Iye, C. Urano, H. Takagi, H. Munekata, Ferromagnetic order induced by photogenerated carriers in magnetic III-V semiconductor heterostructures of (In, Mn)As/GaSb. Phys. Rev. Lett. 78, 4617 (1997)ADSCrossRefGoogle Scholar
  3. 3.
    T. Dietl, H. Ohno, F. Matsukura, J. Cibert, D. Ferrand, Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science 287, 1019 (2000)ADSCrossRefGoogle Scholar
  4. 4.
    D.M. Hoffman, B.K. Meyer, A.I. Ekimov, I.A. Merkulov, A.L. Efros, M. Rosen, G. Couino, T. Gacoin, J.P. Boilot, Gaint internal magnetic fields in Mn doped nanocrystal quantum dots. Solid State Commun. 114, 547 (2000)Google Scholar
  5. 5.
    H. Sato, H. Katayama-Yoshida, Material design for transparent ferromagnets with ZnO-based magnetic semiconductors. Jpn. J. Appl. Phys. 39, L555 (2000)ADSCrossRefGoogle Scholar
  6. 6.
    J.M.D. Coey, M. Venkatesan, C.B. Fitzgerald, Donor impurity band excahnge in dilute ferromagnetic oxides. Nat. Mat. 4, 173 (2005)CrossRefGoogle Scholar
  7. 7.
    K. Ueda, H. Tabata, T. Kawai, Magnetic and electric properties of transition metal doped ZnO films. Appl. Phys. Lett. 79, 988 (2001)ADSCrossRefGoogle Scholar
  8. 8.
    P. Sharma, A. Gupta, K.V. Rao, F.J. Owens, R. Sharma, R. Ahuja, J.M.O. Guillen, B. Johansson, G.A. Gehring, Ferromagnetism above room temperature in bulk and transparent thin films of Mn-doped ZnO. Nat. Mat. 2, 673 (2003)CrossRefGoogle Scholar
  9. 9.
    H.J. Lee, S.Y. Jeong, C.R. Cho, C.H. Park, Study of diluted magnetic semiconductor: Co-doped ZnO. Appl. Phys. Lett. 81, 4020 (2002)ADSCrossRefGoogle Scholar
  10. 10.
    H. Liu, X. Zhang, L. Li, Y.X. Wang, K.H. Gao, Z.Q. Li, R.K. Zheng, S.P. Ringer, B. Zhang, X.X. Zhang, Role of point defects in room-temperature ferromagnetism of Cr-doped ZnO. Appl. Phys. Lett. 91, 072511 (2007)ADSCrossRefGoogle Scholar
  11. 11.
    D.A. Schwartz, N.S. Norberg, Q.P. Nguyen, J.M. Parker, D.R. Gamelin, Magnetic quantum dots: synthesis, spectroscopy, and magnetism of Co\(^{2+}\) and Ni\(^{2+}\) doped ZnO nanocrystals. J. Am. Chem. Soc. 125, 13205 (2003)CrossRefGoogle Scholar
  12. 12.
    S.T. Ochsenbein, Y. Feng, K.M. Whitaker, E. Badaeva, W.K. Liu, X. Li, D.R. Gamelin, Charge controlled magnetism in colloidal doped semiconductor nanocrystals. Nat. Nanotechnol. 4, 681 (2009)ADSCrossRefGoogle Scholar
  13. 13.
    G. Lawes, A.S. Risbaud, A.P. Ramirez, R. Seshadri, Absence of ferromagnetism in Co and Mn substituted polycrystalline ZnO. Phys. Rev. B 71, 045201 (2005)ADSCrossRefGoogle Scholar
  14. 14.
    C.N.R. Rao, F.L. Deepak, Absence of ferromagnetism in Mn- and Co-doped ZnO. J. Mat. Chem. 15, 573 (2005)CrossRefGoogle Scholar
  15. 15.
    Z. Jin, T. Fukumura, M. Kawasaki, K. Ando, H. Saito, T. Sekiguchi, High throughput fabrication of transition metal doped epitaxial ZnO thin films: a series of oxide-diluted magnetic semiconductors and their properties. Appl. Phys. Lett. 78, 3824 (2001)ADSCrossRefGoogle Scholar
  16. 16.
    K.R. Kittilstved, J. Zhao, W.K. Liu, J.D. Bryan, D.A. Schwartz, D.R. Gamelin, Magnetic circular dichroism of ferromagnetic Co2+-doped ZnO. Appl. Phys. Lett. 89, 062510 (2006)ADSCrossRefGoogle Scholar
  17. 17.
    W. Pacuski, D. Ferrand, J. Cibert, C. Deparis, J.A. Gaj, P. Kossacki, C. Morhain, Effect of the s, p-d exchange interaction on the excitons in ZnCoO epilayers. Phys. Rev. B 73, 035214 (2006)ADSCrossRefGoogle Scholar
  18. 18.
    W. Jin, I.K. Lee, A. Kompch, U. Dörfler, M. Winterer, Chemical vapor synthesis and characterization of chromium doped zinc oxide nanopartciles. J. Eur. Ceram. Soc. 27, 4333 (2007)CrossRefGoogle Scholar
  19. 19.
    R. Djenadic, G. Akgül, K. Attenkofer, M. Winterer, Chemical vapor synthesis and structural characterization of nanocrystalline Zn\(_{1-x}\)Co\(_{x}\)O (\(x = 0\)–0.5) particles by X-ray diffraction and X-ray absorption spectroscopy. J. Phys. Chem. C 114, 9207 (2010)CrossRefGoogle Scholar
  20. 20.
    L. Schneider, S.V. Zaitsev, W. Jin, A. Kompch, M. Winterer, M. Acet, G. Bacher, Fabrication and analysis of Cr-doped nanoparticles from the gas phase. Nanotechnology 20, 135604 (2009)ADSCrossRefGoogle Scholar
  21. 21.
    Q. Ou, T. Matsuda, M. Mesko, A. Ogino, M. Nagatsu, Cathodoluminescence property of ZnO nanophosphors prepared by laser ablation. Jpn. J. Appl. Phys. 47, 389 (2008)ADSCrossRefGoogle Scholar
  22. 22.
    L. Schneider, S.V. Zaitsev, G. Bacher, W. Jin, M. Winterer, Recombination dynamics in ZnO nanoparticles produced by chamical vapor synthesis. J. Appl. Phys. 102, 023524 (2007)ADSCrossRefGoogle Scholar
  23. 23.
    S. Polarz, A. Roy, M. Merz, S. Halm, D. Schröder, L. Schneider, G. Bacher, F.E. Kruiss, M. Driess, Chemical vapour synthesis of size-selected zinc oxide nanoparticles. Small 1, 540 (2005)CrossRefGoogle Scholar
  24. 24.
    K. Thonke, T. Gruber, N. Teofilov, R. Schönfelder, A. Waag, R. Sauer, Donor acceptor pair transitions in ZnO substrate material. Phys. E 308, 945 (2001)ADSGoogle Scholar
  25. 25.
    T. Voss, C. Bekeny, L. Wischmeier, H. Gafsi, S. Börner, W. Schade, A.C. Mofor, A. Bakin, A. Waag, Influence of exciton-phonon coupling on the energy position of the near-band-edge photoluminescence in ZnO nanowires. Appl. Phys. Lett. 89, 182107 (2006)ADSCrossRefGoogle Scholar
  26. 26.
    Y. Zhang, B. Lin, X. Sun, Z. Fu, Temperature dependent photoluminescence of nanocrystalline ZnO thin films grown on Si(100) substrates by the sol-gel process. Appl. Phys. Lett. 86, 131910 (2005)ADSCrossRefGoogle Scholar
  27. 27.
    B.D. Zhang, N.T. Binh, Y. Segawa, K. Wakatsuki, N. Usami, Optical properties of ZnO rods formed by metalorganic chemical vapour deposition. Appl. Phys. Lett. 83, 1635 (2003)ADSCrossRefGoogle Scholar
  28. 28.
    D.C. Look, D.C. Reynolds, C.W. Litton, R.L. Jones, D.B. Eason, G. Cantwell, Characterization of homoepitaxial p-type ZnO grown by molecular beam epitaxy. Appl. Phys. Lett. 81, 1830 (2002)ADSCrossRefGoogle Scholar
  29. 29.
    J. Fallert, R. Hauschild, F. Stelzl, A. Urban, M. Wissinger, H. Zhou, C. Klingshirn, H. Kalt, Surface-related luminescence in ZnO nanocrystals. J. Appl. Phys. 101, 073506 (2007)ADSCrossRefGoogle Scholar
  30. 30.
    M. Schirra, R. Schneider, A. Reiser, G.M. Prinz, M. Feneberg, J. Biskupek, U. Kaiser, C.E. Krill, R. Sauer, K. Thonke, Acceptor-related luminescence at 3.314 eV in zinc oxide confined to crystallographic line defects. Physica B 401, 362 (2007)ADSCrossRefGoogle Scholar
  31. 31.
    J.K. Furdyna, Diluted magnetic semiconductors. J. Appl. Phys. 64, R29 (1998)ADSCrossRefGoogle Scholar
  32. 32.
    H.-J. Lee, S.-Y. Jeong, J.-Y. Hwang, C.R. Cho, Ferromagnetism in Li co-doped ZnO:Cr. Europhys. Lett. 64, 797 (2003)ADSCrossRefGoogle Scholar
  33. 33.
    A.C. Tuan, J.D. Bryan, A.B. Pakhomov, V. Shutthanandan, S. Thevuthasan, D.E. McCready, D. Gaspar, M.H. Engelhard, J.W. Rogers Jr., K. Krishnan, D.R. Gamelin, S.A. Chambers, Epitaxial growth and properties of cobalt-doped ZnO on \(\alpha \)-Al\(_{2}\)O\(_{3}\) single crystal substrates. Phys. Rev. B 70, 054424 (2004)Google Scholar
  34. 34.
    H.X. Chen, H.T. Zhang, C.H. Wang, X.G. Luo, P.H. Li, Effect of particle size on magnetic properties of zinc chromite synthesized by sol-gel method. Appl. Phys. Lett. 81, 4419 (2002)ADSCrossRefGoogle Scholar
  35. 35.
    H. Martinho, N.O. Moreno, J.A. Sanjurjo, C. Rettori, A.J. García-Adeva, D.L. Huber, S.B. Oseroff, W. Ratcliff II, S.W. Cheong, P.G. Pagliuso, J.L. Sarrao, G.B. Martins, Magnetic properties of the frustrated AFM spinel ZnCr\(_{2}\)O\(_{4}\) and the spin-glass ZnCdCr\(_{2}\)O\(_{4}\). Phys. Rev B 64, 024408 (2001)Google Scholar
  36. 36.
    Y. Wang, C.-M. Yang, W. Schmidt, B. Spliethoff, E. Bill, F. Schüth, Weakly ferromagnetic ordered mesoporous Co3O4 synthesized by nanocasting from vinyl-functionalized cubic Ia3d mesoporous silica. Adv. Mat. 17, 53 (2005)CrossRefGoogle Scholar
  37. 37.
    T. Dietl, T. Andrearczyk, A. Lipinska, M. Kiecana, M. Tay, Y. Wu, Origin of ferromagnetism in ZnCoO from magnetization and spin-dependent magnetoresistance measurements. Phys. Rev. B 76, 155312 (2007)ADSCrossRefGoogle Scholar
  38. 38.
    S. Colis, H. Bieber, S. Begin-Colin, G. Schmerber, C. Leuvrey, A. Dinia, Magnetic properties of Co-doped ZnO diluted magnetic semiconductors prepared by low-temperature mechanosynthesis. Chem. Phys. Lett. 422, 529 (2006)ADSCrossRefGoogle Scholar
  39. 39.
    Z. Xiao, H. Matsui, N. Hasuike, H. Harima, H. Tabata, Systematic investigation on structures and excitonic-related transitions: an evidence fro ZnCoO alloy film as a wide gap semiconductor. J. Appl. Phys. 103, 043504 (2008)ADSCrossRefGoogle Scholar
  40. 40.
    P. Koidl, Optical absorption of Co\(^{2+}\) in ZnO. Phys. Rev. B 15, 2493 (1977)ADSCrossRefGoogle Scholar
  41. 41.
    A.A. Maksimov, G. Bacher, A. Mc Donald, V.D. Kulakovskii, A. Forchel, C.R. Becker, G. Landwehr, L.W. Molenkamp, Magnetic polarons in a single diluted magnetic semiconductor quantum dot. Phys Rev. B 62, R7767 (2000)Google Scholar
  42. 42.
    Y. Oka, J. Shen, K. Takabayashi, N. Takahashi, H. Misu, I. Souma, R. Pittini, Dynamics of excitonic magnetic polarons in nanostructure diluted magnetic semiconductors. J. Lumin. 83, 83 (1999)CrossRefGoogle Scholar
  43. 43.
    G. Bacher, H. Schömig, M.K. Welsch, S. Zaitsev, V.D. Kulakovskii, A. Forchel, S. Lee, M. Dobrowolska, J.K. Furdyna, B. König, W. Ossau, Optical spectroscopy on individual CdSe/ZnMnSe quantum dots. Appl. Phys. Lett. 79, 524 (2001)ADSCrossRefGoogle Scholar
  44. 44.
    P.R. Kratzert, J. Puls, M. Rabe, F. Henneberger, Growth and magneto-optical properties of sub 10 nm (Cd, Mn)Se quantum dots. Appl. Phys. Lett. 79, 2814 (2001)ADSCrossRefGoogle Scholar
  45. 45.
    M. Scheibner, T.A. Kennedy, L. Worschech, A. Forchel, G. Bacher, T. Slobodskyy, G. Schmidt, L.W. Molenkamp, Coherent dynamics of locally interacting spins in self-assembled CdMnSe/ZnSe quantum dots. Phys. Rev. B 73, 081308 (2006)ADSCrossRefGoogle Scholar
  46. 46.
    S. Mackowski, J. Wrobel, K. Fronc, J. Kossut, F. Pulizzi, P.C.M. Christianen, J.C. Maan, G. Karczewski, Exciton spectroscopy of single CdTe and CdMnTe quantum dots. Phys. Stat. Sol. (b) 229, 493 (2002)Google Scholar
  47. 47.
    M. Goryca, T. Kazimierczuk, M. Nawrocki, A. Golnik, J.A. Gaj, P. Kossacki, P. Wojnar, G. Karczewski, Optical manipulation of a single Mn spin in a CdTe-based quantum dot. Phys. Rev. Lett. 103, 087401 (2009)Google Scholar
  48. 48.
    Y. Terai, S. Kuroda, K. Takita, Self-assembled formation and photoluminescence of CdMnTe quantum dots grown on ZnTe by atomic layer epitaxy. Appl. Phys. Lett. 76, 2400 (2000)ADSCrossRefGoogle Scholar
  49. 49.
    L. Maingault, L. Besombes, Y. Leger, C. Bougerol, H. Mariette, Inserting one single Mn ion into a quantum dot. Appl. Phys. Lett. 89, 193109 (2006)ADSCrossRefGoogle Scholar
  50. 50.
    S. Mackowski, S. Lee, J.K. Furdyna, M. Dobrowolska, G. Prechtl, W. Heiss, J. Kossut, G. Karczewski, Growth and optical properties of Mn-containing II-VI quantum dots. Phys. Stat. Sol. (b) 229, 469 (2002)Google Scholar
  51. 51.
    R.N. Bhargava, D. Gallagher, X. Hong, A. Nurmikko, Optical properties of manganese-doped nanocrystals of ZnS. Phys. Rev. Lett. 72, 416 (1994)ADSCrossRefGoogle Scholar
  52. 52.
    D.J. Norris, N. Yao, F.T. Charnock, T.A. Kennedy, High-quality manganese-doped ZnSe nanocrystals. Nano Lett. 1, 3 (2001)ADSCrossRefGoogle Scholar
  53. 53.
    S.C. Erwin, L.J. Zu, M.I. Haftel, A.L. Efros, T.A. Kennedy, D.J. Norris, Doping semiconductor nanocrystals. Nature 436, 91 (2005)ADSCrossRefGoogle Scholar
  54. 54.
    R. Beaulac, P.I. Archer, X.Y. Liu, S. Lee, G.M. Salley, M. Dobrowolska, J.K. Furdyna, D.R. Gamelin, Spin-polarizable excitonic luminescence in colloidal Mn\(^{2+}\)-doped CdSe quantum dots. Nano Lett. 8, 1197 (2008)ADSCrossRefGoogle Scholar
  55. 55.
    R. Beaulac, L. Schneider, P.I. Archer, G. Bacher, D.R. Gamelin, Light-induced spontaneous magnetization in doped colloidal quantum dots. Science 325, 973 (2009)ADSCrossRefGoogle Scholar
  56. 56.
    J.H. Yu, X.Y. Liu, K.E. Kweon, J. Joo, J. Park, K.T. Ko, D. Lee, S.P. Shen, K. Tivakornsasithorn, J.S. Son, J.H. Park, Y.W. Kim, G.S. Hwang, M. Dobrowolska, J.K. Furdyna, T. Hyeon, Giant Zeeman splitting in nucleation-controlled doped CdSe:Mn\(^{2+}\) quantum nanoribbons. Nat. Mat. 9, 47 (2010)CrossRefGoogle Scholar
  57. 57.
    J. Seufert, G. Bacher, M. Scheibner, A. Forchel, S. Lee, M. Dobrowolska, J.K. Furdyna, Dynamical spin resonse in a semimagnetic quantum dots. Phys. Rev. Lett. 88, 027402 (2002)ADSCrossRefGoogle Scholar
  58. 58.
    P. Wojnar, J. Suffczynski, K. Kowalik, A. Golnik, M. Aleszkiewicz, G. Karczeswski, J. Kossut, Size-dependent magneto-optical effects in CdMnTe diluted magnetic quantum dots. Nanotechnology 19, 235403 (2008)ADSCrossRefGoogle Scholar
  59. 59.
    P.I. Archer, S.A. Santangelo, D.R. Gamelin, Direct observation of sp-d exchange interactions in colloidal Mn\(^{2+}\)- and Co\(^{2+}\)-doped CdSe quantum dots. Nano Lett. 7, 1037 (2007)ADSCrossRefGoogle Scholar
  60. 60.
    R. Beaulac, P.I. Archer, S.T. Ochsenbein, D.R. Gamelin, Doped CdSe quantum dots: new inorganic materials for spin-electronics and spin-photonics. Adv. Func. Mat. 18, 3873 (2008)CrossRefGoogle Scholar
  61. 61.
    O. Labeau, P. Tamarat, B. Lounis, Temperature dependence of the luminescence lifetime of single CdSe/ZnS quantum dots. Phys. Rev. Lett. 90, 257404 (2003)ADSCrossRefGoogle Scholar
  62. 62.
    S.A. Crooker, T. Barrick, J.A. Hollingsworth, V.I. Klimov, Multiple temperature regimes of radiative decay in CdSe nanocrystal quantum dots: intrinsic limits to the dark-exciton lifetime. Appl. Phys. Lett. 82, 2793 (2003)ADSCrossRefGoogle Scholar
  63. 63.
    R. Beaulac, P.I. Archer, J. van Rijssel, A. Meijerink, D.R. Gamelin, Exciton storage by Mn\(^{2+}\) in colloidal Mn\(^{2+}\)-doped CdSe quantum dots. Nano Lett. 8, 2949 (2008)ADSCrossRefGoogle Scholar
  64. 64.
    A.L. Efros, M. Rosen, The electronic structure of semiconductor nanocrystals. Ann. Rev. Mat. Sci. 30, 475 (2000)Google Scholar
  65. 65.
    T.J. Liptay, L.F. Marshall, P.S. Rao, R.J. Ram, M.G. Bawendi, Anomalous Stokes shift in CdSe nanocrystals. Phys. Rev. B 76, 155314 (2007)ADSCrossRefGoogle Scholar
  66. 66.
    T. Kasuya, A. Yanase, Anomalous transport phenomena in Eu-chalcogenide alloys. Rev. Mod. Phys. 40, 684 (1968)ADSCrossRefGoogle Scholar
  67. 67.
    A.V. Kavokin, I.A. Merkulov, D.R. Yakovlev, W. Ossau, G. Landwehr, Exciton localization in semimagnetic semiconductors probed by magnetic polarons. Phys. Rev. B 60, 16499 (1999)ADSCrossRefGoogle Scholar
  68. 68.
    J.A. Gaj, R. Planel, G. Fishman, Relation of magneto-optical properties of free excitons to spin alignment of Mn\(^{2+}\) ions in CdMnTe. Sol. State. Commun. 29, 435 (1979)ADSCrossRefGoogle Scholar
  69. 69.
    O. Goede, W. Heimbrodt, Optical properties of (Zn, Mn) and (Cd, Mn) chalcogenide mixed crystals and superlattices. Phys. Stat. Sol. (b) 146, 11 (1988)Google Scholar
  70. 70.
    I.A. Merkulov, D.R. Yakovlev, K.V. Kavokin, G. Mackh, W. Ossau, A. Waag, G. Landwehr, Hierarchy of relaxation times in the formation of an excitonic magnetic polaron in (CdMn)Te. JETP Lett. 62, 335 (1995)ADSGoogle Scholar
  71. 71.
    T. Dietl, J. Spalek, Effect of thermodynamic fluctuations of magnetization on the bound magnetic polaron in dilute magnetic semiconductors. Phys. Rev. B 28, 1548 (1983)ADSCrossRefGoogle Scholar
  72. 72.
    I.A. Merkulov, G.R. Pozina, D. Coquillat, N. Paganotto, J. Siviniant, J.P. Lascaray, J. Cibert, Parameters of the magnetic polaron state in diluted magnetic semiconductors Cd-Mn-Te with low manganese concentration. Phys. Rev. B 54, 5727 (1996)ADSCrossRefGoogle Scholar
  73. 73.
    G. Bacher, A.A. Maksimov, H. Schömig, M.K. Welsch, V.D. Kulakovskii, P.S. Dorozhkin, A. Forchel, S. Lee, M. Dobrowolska, J.K. Furdyna, Monitoring statistical magnetic fluctuations on the nanometer scale. Phys. Rev. Lett. 89, 127201 (2002)ADSCrossRefGoogle Scholar
  74. 74.
    P.S. Dorozhkin, A.V. Chernenko, V.D. Kulakovskii, A.S. Brichkin, A.A. Maksimov, H. Schoemig, G. Bacher, A. Forchel, S. Lee, M. Dobrowolska, J.K. Furdyna, Longitudinal and transverse fluctuations of magnetization of the excitonic magnetic polaron in a semimagnetic single quantum dot. Phys. Rev. B 68, 195313 (2003)ADSCrossRefGoogle Scholar
  75. 75.
    R. Fiederling, D.R. Yakovlev, W. Ossau, G. Landwehr, I.A. Merkulov, K.V. Kavokin, T. Wojtowicz, M. Kutrowski, K. Grasza, G. Karczewski, J. Kossut, Exciton magnetic polarons in (100)- and (120) oriented semimagnetic digital alloys (Cd, Mn)Te. Phys. Rev. B 58, 4785 (1998)ADSCrossRefGoogle Scholar
  76. 76.
    T. Dietl, P. Peyla, W. Grieshaber, Y. Merle D’Aubigné, Dynamics of spin organization in diluted magnetic semiconductors. Phys. Rev. Lett. 74, 474 (1995)ADSCrossRefGoogle Scholar
  77. 77.
    G. Bacher, L. Schneider, R. Beaulac, P.I. Archer, D.R. Gamelin, Magnetic polaron formation dynamics in Mn\(^{2+}\)-doped colloidal nanocrystals up to room temperature. J. Korean Phys. Soc. 58, 1261 (2011)CrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Electronic Materials and Nanodevices, Faculty of Engineering and CENIDEUniversity of Duisburg-EssenDuisburgGermany

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