Quasiperiodic layers of free-electron metals studied using electron diffraction

Using electron diffraction, we show that free-electron metals, such as sodium and potassium, form a highly regular quasiperiodic monolayer on the fivefold surface of icosahedral Al-Pd-Mn and that the quasiperiodicity propagates up to the second layer in sodium. Our photoelectron spectroscopy results show that the quasicrystalline alkali-metal adlayer does not exhibit a pseudogap near the Fermi level thought to be characteristic for the electronic structure of quasicrystalline materials. Calculations based on density functional theory provide a model structure for the quasicrystalline alkali-metal monolayer and confirm the absence of a pseudogap. Disciplines Metallurgy Comments This article is from Physical Review B 79 (2009): 134206, doi:10.1103/PhysRevB.79.134206. Authors A. K. Shukla, R. S. Dhaka, S. W. D'Souza, Sanjay Singh, D. Wu, Thomas A. Lograsso, M. Krajčí, J. Hafner, K. Horn, and S. R. Barman This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/ameslab_pubs/62 Quasiperiodic layers of free-electron metals studied using electron diffraction A. K. Shukla,1 R. S. Dhaka,1 S. W. D’Souza,1 Sanjay Singh,1 D. Wu,2 T. A. Lograsso,2 M. Krajčí,3,4 J. Hafner,4 K. Horn,5 and S. R. Barman1 1UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452001, India 2Ames Laboratory U.S. DOE, Iowa State University, Ames, Iowa 50011-3020, USA 3Institute of Physics, Slovak Academy of Sciences, SK-84511 Bratislava, Slovak Republic 4Center for Computational Materials Science, Universität Wien, A-1090 Wien, Austria 5Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany Received 19 November 2008; revised manuscript received 9 March 2009; published 29 April 2009 Using electron diffraction, we show that free-electron metals, such as sodium and potassium, form a highly regular quasiperiodic monolayer on the fivefold surface of icosahedral Al-Pd-Mn and that the quasiperiodicity propagates up to the second layer in sodium. Our photoelectron spectroscopy results show that the quasicrystalline alkali-metal adlayer does not exhibit a pseudogap near the Fermi level thought to be characteristic for the electronic structure of quasicrystalline materials. Calculations based on density functional theory provide a model structure for the quasicrystalline alkali-metal monolayer and confirm the absence of a pseudogap. DOI: 10.1103/PhysRevB.79.134206 PACS number s : 79.60.Dp, 73.20.At, 61.05.jh, 71.23.Ft