Magnetic clusters in semiconductors
Collaboration:
Dr. A. Ney, Universität Duisburg-Essen, now at University of Linz
Dr. C. Sürges, KIT
Abstract
According to the necessity of ferromagnetic semiconductor materials for spintronics, the project is focused on the investigation of magnetic clusters embedded in semiconductors. The new aspects of the project are given by the investigation of the effect of magnetic nanoparticles on the charge carriers and of magnetic phenomena induced by implantation defects. The analysis is focused on high-resolution techniques using photon beams. These techniques will allow the clear identification of secondary phases as well as the element specific investigation of the electronic structure.
Figures
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The presence of a ferromagnetic diluted magnetic semiconductor (DMS) based on ZnO can be confused with non-detectable metallic nanoparticles.
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Non - systematic dependence of the magnetisation on the particle size of MnSi nanoparticles formed via Mn implantation into Si has been observed.
The nanoparticles MnSi1.7 show increase in size with increasing Mn fluence ((a) 1×1015 cm-2, (b) 1×1016 cm-2 and (c) 5×1016 cm-2. ). Only for the middle fluence, however, superparamagnetism can be observed. |
Publications
Advanced spectroscopic synchrotron techniques to unravel the intrinsic properties of dilute magnetic oxides: the case of Co:ZnO
A. Ney, M. Opel, T. C. Kaspar, V. Ney, S. Ye, K. Ollefs, T. Kammermeier, S. Bauer, K.- W. Nielsen, S. T. B. Goennenwein, M. H. Engelhard, S. Zhou, K. Potzger, J. Simon, W. Mader, S. M. Heald, J. C. Cezar, F. Wilhelm, A. Rogalev, R. Gross, and S: A. Chambers,
N. J. Phys. 12, 013020 (2010).
Memory effect of Mn5Ge3 nanomagnets embedded inside a Mn-diluted Ge matrix
Shengqiang Zhou, A. Shalimov, K. Potzger, N. M. Jeutter, C. Baehtz, M. Helm, J. Fassbender, and H. Schmidt,
Appl. Phys. Lett. 95, 192505 (2009).
MnSi1.7 nanoparticles embedded in Si: Superparamagnetism with collective behavior
Shengqiang Zhou, A. Shalimov, K. Potzger, M. Helm, J. Fassbender, and H. Schmidt,
Phys. Rev. B 80, 174423 (2009).
Spinel ferrite nanocrystals embedded inside ZnO: Magnetic, electronic, and magnetotransport properties
S. Q. Zhou, K. Potzger, Q. Y. Xu, K. Kuepper, G. Talut, D. Marko, A. Muecklich, M. Helm, J. Fassbender, E. Arenholz, and H. Schmidt
Phys. Rev. B 80, 094409 (2009).
Spin-dependent transport in nanocomposite C:Co films
S. Q. Zhou, M. Berndt, D. Buerger, V. Heera, K. Potzger, G. Abrasonis, G. Radnoczi, G. J. Kovacs, A. Kolitsch, M. Helm, J. Fassbender, W. Moeller, and H. Schmidt
Act. Mater. 57, 4758 (2009).
Magnetism of carbon doped Mn5Si3 and Mn5Ge3 films
C. Suergers, K. Potzger, and G. Fischer
J. Chem. Sci. 121, 173 (2009).
Amorphous clusters in Co implanted ZnO induced by boron preimplantation
K. Potzger, A. Shalimov, S. Q. Zhou, H. Schmidt, A. Muecklich, M. Helm, J. Fassbender, M. Liberati, and E. Arenholz
J. Appl. Phys. 105, 123917 (2009).
Inverse spinel ZnFe2O4 nanoparticles synthesized by ion implantation and post-annealing: An investigation using X-ray spectroscopy and magneto-transport
S. Zhou, K. Potzger, D. Buerger, K. Kuepper, M. Helm, J. Fassbender, and H. Schmidt
Nucl. Instrum. Meth. B 267, 1620 (2009).
Ferromagnetic transition metal implanted ZnO: A diluted magnetic semiconductor?
S. Q. Zhou, K. Potzger, Q. Y. Xu, G. Talut, M. Lorenz, W. Skorupa, M. Helm, J. Fassbender, M. Grundmann, and H. Schmidt
Vacuum 83, S13 (2009).
Non-DMS related ferromagnetism in transition metal doped zinc oxide
K. Potzger and S. Q. Zhou
Phys. Stat. Sol. B 246, 1147 (2009).
Paramagnetism in Co-doped ZnO films
Q. Y. Xu, S. Zhou, D. Marko, K. Potzger, J. Fassbender, M. Vinnichenko, M. Helm, H. Hochmuth, M. Lorenz, M. Grundmann, and H. Schmidt
J. Phys. D Appl. Phys. 42, 085001 (2009).
Ferromagnetic structurally disordered ZnO implanted with Co ions
K. Potzger, S. Q. Zhou, Q. Y. Xu, A. Shalimov, R. Groetzschel, H. Schmidt, A. Muecklich, M. Helm, and J. Fassbender
Appl. Phys. Lett. 93, 232504 (2008).
Room temperature ferromagnetism in carbon-implanted ZnO
S. Q. Zhou, Q. Y. Xu, K. Potzger, G. Talut, R. Groetzschel, J. Fassbender, M. Vinnichenko, J. Grenzer, M. Helm, H. Hochmuth, M. Lorenz, M. Grundmann, and H. Schmidt
Appl. Phys. Lett. 93, 232507 (2008).
High cluster formation tendency in Co implanted ZnO
K. Potzger, K. Kuepper, Q. Y. Xu, S. Q. Zhou, H.Schmidt, M.Helm, and J. Fassbender
J. Appl. Phys. 104, 023510 (2008).
Magnetic order by C-ion implantation into Mn5Si3 and Mn5Ge3 and its lateral modification
C. Suergers, K. Potzger, T. Strache, W. Moeller, G. Fischer, N. Joshi, and H. von Loehneysen
Appl. Phys. Lett. 93, 062503 (2008).
X-ray Spectroscopic and Magnetic Investigation of C:Ni Nanocomposite Films Grown by Ion Beam Cosputtering
G. Abrasonis, A. C. Scheinost, S. Zhou, R. Torres, R. Gago, I. Jiménez, K. Kuepper, K. Potzger, M. Krause, A. Kolitsch, W. Moller, S. Bartkowski, M. Neumann, and R. R. Gareev
J. Phys. Chem. C 112, 12628 (2008).
Crystallographically oriented Fe nanocrystals formed in Fe-implanted TiO2
Shengqiang Zhou, G. Talut, K. Potzger, A. Shalimov, J. Grenzer, W. Skorupa, M. Helm, J. Fassbender, E. Cizmar, S. A. Zvyagin, and J. Wosnitza
J. Appl. Phys. 103, 083907 (2008).
Using x-ray diffraction to identify precipitates in transition metal doped semiconductors
Shengqiang Zhou, K. Potzger, G. Talut, J. von Borany, W. Skorupa, M. Helm, and J. Fassbender,
J. Appl. Phys. 103, 07D530 (2008).
Structural and magnetic properties of Tb implanted ZnO single crystals
Shengqiang Zhou, K. Potzger, A. Mücklich, F. Eichhorn, M. Helm, W. Skorupa, J. Fassbender
Nucl. Instrum. Meth. B 266, 589 (2008).
Fe implanted ZnO: Magnetic precipitates versus dilution
S.Q. Zhou, K. Potzger, G. Talut, H. Reuther, J. von Borany, W. Skorupa, M. Helm, J. Fassbender, N. Volbers, M. Lorenz, T. Hermannsdörfer
J. App. Phys. 103, 023902 (2008).
Crystallographically oriented Co and Ni nanocrystals inside ZnO formed by ion implantation and post-annealing
S. Q. Zhou, K. Potzger, J. von Borany, R. Grötzschel, W. Skorupa, M. Helm, J. Fassbender
Phys. Rev. B 77, 035209 (2008) and Virt. J. Nanoscale Sci. and Technol., Feb. 2008.
Suppression of secondary phase formation in Fe implanted ZnO single crystals
K. Potzger, Shengqiang Zhou, H. Reuther, K. Kuepper, G. Talut, M. Helm, J. Fassbender, and J. D. Denlinger,
Appl. Phys. Lett. 91, 062107 (2007)
Absence of ferromagnetism in V-implanted ZnO single crystals
Shengqiang Zhou, K. Potzger, H. Reuther, K. Kuepper, W. Skorupa, M. Helm, J. Fassbender
J. Appl. Phys.101, 033906 (2007)
Crystallographically oriented magnetic ZnFe2O4 nanoparticles synthesized by Fe implantation into ZnO
Shengqiang Zhou, K. Potzger, H. Reuther, G. Talut, F. Eichhorn, J. von Borany, W. Skorupa, M. Helm, J. Fassbender
J. Phys. D: Appl. Phys, 40, 964 (2007)
The effect of flash lamp annealing on Fe implanted ZnO single crystals
K. Potzger, W. Anwand , H. Reuther , Shengqiang Zhou , G. Talut , G. Brauer , W. Skorupa , J. Fassbender
J. Appl. Phys., 101, 033906 (2007).
Crystalline Ni nanoparticles as the origin of ferromagnetism in Ni implanted ZnO crystals
Shengqiang Zhou, K. Potzger, Gufei Zhang, F. Eichhorn, W. Skorupa, M. Helm, and J. Fassbender
J. Appl. Phys. 100, 114304 (2006).
Ferromagnetic Gd-implanted ZnO single crystals
K. Potzger, Shengqiang Zhou, F. Eichhorn, M. Helm, W. Skorupa, A. Mücklich, J. Fassbender, T. Herrmannsdörfer, and A. Bianchi
J. Appl. Phys. 99, 063906 (2006).
Fe implanted ferromagnetic ZnO
K. Potzger, Shengqiang Zhou, H. Reuther, A. Mücklich, F. Eichhorn, N. Schell, W. Skorupa, M. Helm, and J. Fassbender, T. Herrmannsdörfer and T. P. Papageorgiou
Appl. Phys. Lett. 88, 052508 (2006).
Structural and magnetic properties of Mn-implanted Si
Shengqiang Zhou, K. Potzger, Gufei Zhang, A. Muecklich, F. Eichhorn, N. Schell, R. Groetzschel, B. Schmidt, W. Skorupa, M. Helm, J. Fassbender
Phys. Rev. B 75, 085203 (2007).