Band gaps, crystal-field splitting, spin-orbit coupling, and exciton binding energies in ZnO under hydrostatic pressure

1995 ◽  
Vol 94 (4) ◽  
pp. 251-254 ◽  
Author(s):  
A. Mang ◽  
K. Reimann ◽  
St. Rübenacke
2018 ◽  
Vol 112 (7) ◽  
pp. 071903 ◽  
Author(s):  
Nicolas Chauvin ◽  
Amaury Mavel ◽  
Ali Jaffal ◽  
Gilles Patriarche ◽  
Michel Gendry

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Teresa Feldmaier ◽  
Pascal Strobel ◽  
Michael Schmid ◽  
Philipp Hansmann ◽  
Maria Daghofer

2017 ◽  
Vol 50 (2) ◽  
pp. 576-584 ◽  
Author(s):  
Meng Wu ◽  
Jin-Cheng Zheng ◽  
Hui-Qiong Wang

Configuration interaction cluster calculation can effectively reproduce the experimentally measured Ti L 23-edge absorption spectrum for the TiO6 cluster LaTiO3. A further investigation of the hybridization strength and charge-transfer energy effects on the multiplet structures suggests that LaTiO3 should be classified as an intermediate state between the charge-transfer and Mott–Hubbard regimes. Detailed temperature-dependent simulations of absorption spectra support the lifting of Ti t 2g orbital degeneracy and crystal field splitting. The spin–orbit coupling scenario is ruled out, even though 3d spin–orbit coupling can reproduce the experimental spectrum without including temperature. A combined polarization- and crystal-field-splitting-dependent analysis indicates asymmetric ΔCF–orbital interactions for the TiO6 cluster [Ti3+:3d 1(t 2g 1)], different from the orbital–lattice interactions reported for the NiO6 cluster [Ni3+:3d 7(t 2g 6 eg 1)]. The orbital polarization is defined in terms of the normalized electron occupancies in orbitals with xy and xz(yz) symmetries, and nearly complete orbital polarization (more than 75%) is observed, indicating strongly reduced orbital fluctuations due to the correlation effects. This is consistent with the density of states for titanates based on local density approximation plus dynamical mean-field theory calculations.


1977 ◽  
Vol 55 (10) ◽  
pp. 937-942 ◽  
Author(s):  
A. F. Leung ◽  
Ying-Ming Poon

The absorption spectra of UCl5 single crystal were observed in the region between 0.6 and 2.4 μm at room, 77, and 4.2 K temperatures. Five pure electronic transitions were assigned at 11 665, 9772, 8950, 6643, and 4300 cm−1. The energy levels associated with these transitions were identified as the splittings of the 5f1 ground configuration under the influence of the spin–orbit coupling and a crystal field of C2v symmetry. The number of crystal field parameters was reduced by assuming the point-charge model where the positions of the ions were determined by X-ray crystallography. Then, the crystal field parameters and the spin–orbit coupling constant were calculated to be [Formula: see text],[Formula: see text], [Formula: see text], and ξ = 1760 cm−1. The vibronic analysis showed that the 90, 200, and 320 cm−1 modes were similar to the T2u(v6), T1u(v4), and T1u(v3) of an UCl6− octahedron, respectively.


2015 ◽  
Vol 3 (17) ◽  
pp. 9232-9240 ◽  
Author(s):  
C. Katan ◽  
L. Pedesseau ◽  
M. Kepenekian ◽  
A. Rolland ◽  
J. Even

Metal and halogen substitution in hybrid perovskites reveals the interplay between spin–orbit coupling, structural distortions and many-body effects controlling band-gaps.


ACS Nano ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 1619-1624 ◽  
Author(s):  
Xiuming Dou ◽  
Kun Ding ◽  
Desheng Jiang ◽  
Xiaofeng Fan ◽  
Baoquan Sun

It is shown in the first part how the basic formalism of the theory of spin-orbit coupling in the band theory of crystals can be deduced at once from the Dirac equation without the usual ambiguities over improper rotations associated with the formalism based on the Pauli-Schrödinger equation. In the second part it is shown that the original proofs of the time-reversal theorems given by Wigner are unnecessarily complicated.


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