Structural phase transition associated with van Hove singularity in 5d transition metal compound IrTe2

T Qian, H Miao, Z J Wang, X Shi, Y B Huang, P Zhang, N Xu, L K Zeng, J Z Ma, P Richard, M Shi, G Xu (+5 others)
2014 New Journal of Physics  
Comprehensive studies of the electronic states of Ir 5d and Te 5p have been performed to elucidate the origin of the structural phase transition in IrTe2 by combining angle-resolved photoemission spectroscopy and resonant inelastic X-ray scattering. While no considerable changes are observed in the configuration of the Ir 5d electronic states across the transition, indicating that the Ir 5d orbitals are not involved in the transition, we reveal a van Hove singularity at the Fermi level (EF)
more » ... ermi level (EF) related to the Te px+py orbitals, which is removed from EF at low temperatures. The wavevector connecting the adjacent saddle points is consistent with the in-plane projection of the superstructure modulation wavevector. These results can be qualitatively understood with the Rice-Scott "saddle-point" mechanism, while effects of the lattice distortions need to be additionally involved.
doi:10.1088/1367-2630/16/12/123038 fatcat:d3xhljufyjep5o46rly66dt3sm