Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 23: Micro- and Nanostructured Magnetic Materials

MA 23.3: Vortrag

Mittwoch, 2. April 2014, 10:00–10:15, HSZ 403

Magnetic order triggered by hydrogenation of Li-doped ZnO microwires — •Israel Lorite¹, Benjamin Straueb², Parmod Kumar¹, Carlos Zandalazini², Hendrik Ohldag³, Silvia de Heluani², and Pablo Esquinazi¹ — ¹Division of Superconductivity and Magnetism, University of Leipzig, Leipzig, Germany — ²Laboratorio de Fisica de Solido, Universidad de Tucuman, Tucuman, Argentina — ³SLAC National Accelerator Laboratory, Menlo Park, Stanford University, CA, USA

Cation and oxygen vacancies, as well as hydrogen can play an important role in the magnetic order observed in nominally non-magnetic oxides like ZnO, a phenomenon called nowadays as defect-induced magnetism (DIM). In this work we have produced microwires of ZnO, pure and doped with 1...7 atom.% Li. The magnetic characterization of the wires has been realized using magnetoresistance, superconducting quantum interferometer device (SQUID), photoconductivity and x-ray magnetic circular dichroism (XMCD). Photoluminescence spectroscopy was performed to elucidate the incidence of defects. Our results indicate that hydrogenation of pure ZnO microwires triggers magnetic order at temperatures below 100K. Room temperature magnetic order is observed after hydrogenation of Li-doped ZnO with a Li concentration above 1%, in agreement with the expected minimum distance between localized defects necessary to trigger magnetic order. Hydrogenation is a simpler and more effective way to trigger DIM in nominally non-magnetic oxides microstructures, paving the way for possible future applications of this phenomenon.