Premium
Hybridization Gap and Dresselhaus Spin Splitting in EuIr 4 In 2 Ge 4
Author(s) -
Calta Nicholas P.,
Im Jino,
Rodriguez Alexandra P.,
Fang Lei,
Bugaris Daniel E.,
Chasapis Thomas C.,
Freeman Arthur J.,
Kanatzidis Mercouri G.
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201504315
Subject(s) - tetragonal crystal system , band gap , chemistry , intermetallic , atomic orbital , condensed matter physics , electronic structure , valence (chemistry) , electronic band structure , orbital hybridisation , spin–orbit interaction , crystallography , crystal structure , electron , physics , molecular orbital theory , organic chemistry , alloy , quantum mechanics
EuIr 4 In 2 Ge 4 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 E g =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 Eu 2+ ions present in the structure, which do not play a role in gap formation, order antiferromagnetically at 2.5 K.