Title :
Fe implanted ferromagnetic ZnO
Author :
Potzger, K. ; Zhou, S. ; Reuther, H. ; Mucklich, A. ; Eichhorn, F. ; Schell, N. ; Skorupa, W. ; Helm, M. ; Fassbender, J. ; Herrmannsdorfer, T. ; Papageorgiou, T.
Author_Institution :
Inst. of Ion Beam Phys. & Mater. Res., Dresden
Abstract :
Room-temperature ferromagnetism has been induced within ZnO single crystals by implant-doping with Fe ions.The four samples implanted initially have been analyzed using SQUID (superconducting quantum interference device) magne-tometry. It was found that only two of them, i.e. the HFHT and the LFLT samples exhibit a pronounced hysteresis loop upon magnetization reversal at 5 K and 300 K. As was found using synchrotron X-ray diffraction, transmission electron microscopy and conversion electron Mossbauer spectroscopy (CEMS) the origin of the ferromagnetic properties of the HFHT-sample are tiny alpha-Fe-nanoparticles with a mean diameter of 8 nm. At 180 keV Fe implanted ZnO single crystals can develop ferromagnetic properties that are either caused by alpha-Fe nanoparticles or an indirect coupling of the Fe ions in a DMS system, depending on the details of ion fluence and implantation temperature. In any case sophisticated structural characterization is required in order to rule out secondary phases.
Keywords :
II-VI semiconductors; Mossbauer effect; X-ray diffraction; doping; ferromagnetic materials; iron; magnetic hysteresis; magnetic impurities; magnetic structure; magnetisation reversal; nanoparticles; semimagnetic semiconductors; transmission electron microscopy; zinc compounds; HFHT samples; LFLT samples; SQUID; ZnO:Fe; conversion electron Mossbauer spectroscopy; electron volt energy 180 keV; ferromagnetism; hysteresis loop; implant doping; magnetization reversal; magnetometry; nanoparticles; size 8 nm; sophisticated structural characterization; superconducting quantum interference device; synchrotron X-ray diffraction; temperature 293 K to 298 K; temperature 5 K to 300 K; transmission electron microscopy; Crystals; Electrons; Hysteresis; Interference; Iron; Magnetic analysis; Magnetization reversal; SQUIDs; Superconducting devices; Zinc oxide;
Conference_Titel :
Magnetics Conference, 2006. INTERMAG 2006. IEEE International
Conference_Location :
San Diego, CA
Print_ISBN :
1-4244-1479-2
DOI :
10.1109/INTMAG.2006.375642
