title: Electron paramagnetic resonance study of ZnO varistor material.
abstract: Matsuoka-type zinc oxide (ZnO) varistor material was synthesized using a conventional solid-state reaction method. X-band electron paramagnetic resonance (EPR) data revealed that Mn ions substitute in the ZnO lattice with a 2+ paramagnetic state. Co ions with either 3+ or 2+ oxidation states are only detectable at cryogenic temperatures. A Cr(3+) EPR signal was strongly suppressed or masked by a Mn(2+) signal. Photoluminescence and electrical results indicated that the varistor sample has fewer intrinsic defects and much higher resistivity as compared to undoped and metal-ion doped ZnO.
authors.affiliation: Institut für Materialwissenschaft, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, D-64287 Darmstadt, Germany.
authors.forename: Raschid
authors.initials: R
authors.lastname: Baraki
authors.forename: Paul
authors.initials: P
authors.lastname: Zierep
authors.forename: Emre
authors.initials: E
authors.lastname: Erdem
authors.forename: Stefan
authors.initials: S
authors.lastname: Weber
authors.forename: Torsten
authors.initials: T
authors.lastname: Granzow
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D049449:Luminescence; D008280:Magnetics; D008345:Manganese / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D008345:Manganese; D015034:Zinc Oxide