Surface lattice dynamics of the 122-type iron pnictides

ORAL

Abstract

We present a systematic High Resolution Electron Energy Loss Spectra (HREELS) study of the surfaces lattice dynamics of the cleaved single crystals of the parent compounds AFe$_{2}$As$_{2}$ (A=Ba, Ca) as a function of temperature and sample treatment. The different phonon signatures on the competing surface reconstructions 1$\times $2 phase and ($\surd $2x$\surd $2)R45$^{^{\circ}}$ phase are studied. For Ba there are two optical phonon modes are observed at 18 and 29 meV, which can be identified as the $A_{1g}$ and $B_{1g}$ vibrations of the As and Fe atoms, respectively. A detailed discussion is given in terms of the interplay between the spin and lattice in this novel system

*Supported by NSF DMR-1002622.

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Authors

  • Jing Teng

    • Louisiana State University

  • Chen Chen

    • Louisiana State University

  • Guorong Li

    • Louisiana State University, Baton Rouge, LA 70803, USA
    • Dept. of Physics, Louisiana State University, Baton Rouge, LA 70802, USA
    • Louisiana State University

  • Amar Karki

    • Dept. of Physics, Louisiana State University, Baton Rouge, LA 70802, USA
    • Louisiana State University

  • Jiandi Zhang

    • Louisiana State University, Baton Rouge, LA 70803, USA
    • Dept. of Physics, Louisiana State University, Baton Rouge, LA 70802, USA
    • Louisiana State University

  • Rongying Jin

    • Louisiana State University
    • Louisiana State University, Baton Rouge, LA 70803, USA
    • Department of Physics and Astronomy, Louisiana State University
    • Louisiana State University, Baton Rouge LA
    • Louisiana State University, USA
    • Dept. of Physics, Louisiana State University, Baton Rouge, LA 70802, USA

  • Ward Plummer

    • Louisiana State University, Baton Rouge, LA 70803, USA
    • Louisiana State University
    • Department of Physics and Astronomy, Louisiana State University
    • Louisiana State University, Baton Rouge LA
    • Depart. of Physics, Louisiana State University, Baton Rouge, LA 70802, USA