Hybridization Gap and Dresselhaus Spin Splitting in EuIr4In2Ge4

Nicholas P. Calta, Jino Im, Alexandra P. Rodriguez, Lei Fang, Daniel E. Bugaris, Thomas C. Chasapis, Arthur J. Freeman, Mercouri G. Kanatzidis

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5 Citations (Scopus)

Abstract

EuIr4In2Ge4 is a new intermetallic semiconductor that adopts a non-centrosymmetric structure in the tetragonal {I\bar 42m} space group with unit cell parameters a=6.9016(5) Å and c=8.7153(9) Å. The compound features an indirect optical band gap Eg=0.26(2) eV, and electronic-structure calculations show that the energy gap originates primarily from hybridization of the Ir 5d orbitals, with small contributions from the Ge 4p and In 5p orbitals. The strong spin-orbit coupling arising from the Ir atoms, and the lack of inversion symmetry leads to significant spin splitting, which is described by the Dresselhaus term, at both the conduction- and valence-band edges. The magnetic Eu2+ ions present in the structure, which do not play a role in gap formation, order antiferromagnetically at 2.5 K. An intermetallic semiconductor with a non-centrosymmetric structure and the chemical formula EuIr4In2Ge4 is reported. The band gap is a direct result of strong Ir-Ir bonding, and strong spin-orbit coupling effects lead to spin splitting at the conduction- and valence-band edges, which is described by the Dresselhaus term.

Original languageEnglish
Pages (from-to)9186-9191
Number of pages6
JournalAngewandte Chemie - International Edition
Volume54
Issue number32
DOIs
Publication statusPublished - Aug 1 2015

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Keywords

  • X-ray diffraction
  • crystal growth
  • electronic structure
  • hybridization
  • intermetallic phases

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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