Ferromagnetism in transition metal doped ZnO

• Applicant: Professorin Dr. Heidemarie Schmidt
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 28587221

Room temperature ferromagnetism in transparent magnetic oxide semiconductors could pave the way to exploit spin in addition to charge in future spintronic devices. The goal of the project is the preparation of ferromagnetic ZnO under optimized PLD growth conditions and postgrowth annealing. Stringent experimental methods are needed to ascertain intrinsic ferromagnetism in typically 1 /mi thick ZnO films obtained by epitaxial growth on transparent substrates or by magnetic ion implantation into ZnO single crystals. For example anomalous Hall effect or Andreev reflection measurements can be used to probe intrinsic magnetization or spin polarization in magnetic ZnO, respectively. We project to build a magneto-optical Kerr effect magnetometer with a HeCd laser (UV-MOKE) and a photoelastic modulator for measuring complex Faraday rotation angles with a resolution better than 10~6. We aim to determine the magnetic anisotropy averaged over several magnetic domains and of single magnetic domains in ferromagnetic ZnO. Furthermore, we aim to measure hysteresis loops from the surface near region in ferromagnetic ZnO and to evaluate quantitatively the magnetization as a function of the applied longitudinal or transversal magnetic field using the results from subsidiary spectral ellipsometry measurements and the transfer matrix method.

• DFG Programme: Research Grants