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

–

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