Berlin 2012 – wissenschaftliches Programm
MA 22.5: Vortrag
Mittwoch, 28. März 2012, 10:30–10:45, EB 301
Heusler topological insulators: Electronic structure and transport properties — •C. Shekhar1, S. Ouardi2, G. H. Fecher1, 2, A. K. Nayak1, A. Gloskovskii2, E. Ikenaga3, S. Ueda4, K. Kobayashi4, and C. Felser1,2 — 1Max Planck Institute for Chemical Physics of Solids, Dresden — 2Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg - University, Mainz — 3Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo, Japan — 4National Institute for Materials Science, SPring-8, Hyogo, Japan
Topological insulators have a high potential for spintronics devices and quantum computation. Various Heusler compounds crystallize in a fcc structure of the C1b type and consist of 2 transition metals and a main group element. If the compounds contain heavy metals and a lanthanide element then they exhibit extraordinary physical properties including superconductivity, half-metallic, semiconducting-like behavior, giant magnetoresistivity, heavy fermion state and zero band gap. The density of states of XMZ Heusler compounds (M = Gd, Lu, X= Au, Pt, Pd and Z= Pb, Sb, Bi) were investigated by hard X-ray photoelectron spectroscopy. The comparison of the experimental results to calculations gives evidence for the zero band gap state of the compounds. Further, the temperature dependence of electrical conductivity, magneto resistance, Hall mobility, Seebeck coefficient and thermal conductivity were investigated. The compounds exhibit a high Hall mobility and a linear magnetoresistance (MR). The observed linear MR is a quantum MR and due to the topological insulator state.