Positron Annihilation Induced Auger and Gamma Spectroscopy of Catalytically Important Surfaces

ORAL

Abstract

The annihilation of positrons with core electrons results in unique signatures in the spectra of Auger-electron and annihilation-gamma rays that can be used to make clear chemical identification of atoms at the surface. Because positrons implanted at low energies are trapped with high efficiency in the image-correlation well where they are localized just outside the surface it is possible to use annihilation induced Auger and Gamma signals to probe the surfaces of solids with single atomic layer depth resolution. In this talk we will report recent applications of Positron Annihilation Induced Auger Electron Spectroscopy (PAES) and Auger-Gamma Coincidence Spectroscopy (AGCS) to the study of surface structure and surface chemistry. Our research has demonstrated that PAES spectra can provide new information regarding the composition of the top-most atomic layer. Applications of PAES to the study of catalytically important surfaces of oxides and wide band-gap semiconductors including TiO$_{2}$, SiO$_{2,}$Cu$_{2}$O, and SiC will be presented. We conclude with a discussion of the use of Auger-Gamma and Gamma-Gamma coincidence spectroscopy for the study of surfaces at pressures closer to those found in practical chemical reactors. Research supported by the Welch Foundation Grant Number Y-1100.

–

Authors

  • A.H. Weiss

    University of Texas, Arlington, Department of Physics, The University of Texas at Arlington, Department of Physics, University of Texas, Arlington, University of Texas at Arlington

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School

  • Dana Dunn

    University of Texas at Arlington, Peoples Friendship University of the Russia, TSAAPT Officer, University of Texas at El Paso, Department of Chemistry, Stephen F. Austin University, Department of Physics, Stephen F. Austin University, Highland Park High School, Dallas, Texas, Lamar High School, Arlington, Texas, Angelo State University, Abilene Christian University, Southern Nazarene University, Texas Tech University, Sam Houston State University, University of Texas at Austin, Cornell University, University of Houston, University of Texas Center for Relativity, Ion Beam Modification and Analysis Laboratory (IBMAL), University of North Texas, University of North Texas, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, NanoTech Institute, University of Texas at Dallas, Richardson, TX 75083, Department of Physics, The University of Texas at Arlington, Arlington, Texas 76019, Department of Physics, University of Texas at Arlington, Arlington, TX, 76019, UTA High Energy Physics Group, Univ. of Texas, Arlington, USA, KAERI Korea, Changwon National Univ., Korea, Rutgers University, Iowa State University, Rigaku/MSC, Texas Christian University, Dept. of Physics, Changwon National University, Department of Physics, University of North Texas, Department of Chemistry and Biochemistry, Arizona State University, Research Center, Philip Morris USA, Harrington Department Bioengineering Arizona State University, Universidad Autonoma de Colima, Universidad de Buenos Aires, Department of Physics, University of Texas, Arlington, Chair, Department of Physics, University of Texas at Arlington, Dean of Science, University of Texas at Arlington, President, University of Texas at Arlington, Department of Electrical Engineering, Princeton University, Department of Physics, Texas A\&M University, NanoFAB Center and Electrical Engineering Department, University of Texas at Arlington, University of Texas at San Antonio, SEMATECH, University of Texas at Dallas, CINVESTAV Queretaro, Mexico and University of Texas at Dallas, Texas A\&M University, Departamento de F\'isica, FCEN, Universidad de Buenos Aires, Freescale Semiconductor, Inc., Department of Physics, UT Austin, Physics Department, The University of Texas at Arlington, Department of Physics, University of Texas at Arlington, Tolar High School, Granbury High School