Effect of Heating and H gas Exposure on MgZnO Nanoparticle Conductivity.

ORAL

Abstract

Changes in the conductivity of Mg$_{x}$Zn$_{1-x}$O (x = 0.15) nanoparticles as a function gas exposure and temperature are reported. The nanoparticles were prepared using wet chemical techniques on insulating thermally grown SiO$_{x}$ Si substrates. Contact to the nanoparticle film was by gold wires laid across about 2 mm apart. The experiments were performed in a custom-built environmental chamber with the ability to evacuate or introduce various gases. For these experiments, the temperature was varied over a range of about 300 K to 420 K. Our measurements showed history-dependant behavior in changes of the conductance of the nanoparticle film. When the device was heated to $\sim $120 K in vacuum or in an Ar the current increased by the same amount. When repeated with H$_{2}$, the current increase was less. Initially, the effect was quite pronounced with a relative change by a factor of 20. With repetitions of the experiments, the same effect was observed but to a lesser degree suggesting a saturation phenomena. When the experiment was modified so that the H$_{2}$ gas was introduced at a high temperature to an evacuated chamber the current dropped but not by the same degree as before. A similar response to exposure to H$_{2}$ was found for exposure to O$_{2}$. Possible explanations for the observations will be presented.

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Authors

  • Chris Berven

    University of Idaho

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary