scholarly journals Common microscopic origin of the phase transitions in Ta2NiS5 and the excitonic insulator candidate Ta2NiSe5

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lukas Windgätter ◽  
Malte Rösner ◽  
Giacomo Mazza ◽  
Hannes Hübener ◽  
Antoine Georges ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Lattice Distortion ◽  
Structural Phase ◽  
Microscopic Investigation ◽  
First Principles Calculations ◽  
Excitonic Insulator ◽  
Insulating Phase ◽  
Microscopic Origin

AbstractThe structural phase transition in Ta2NiSe5 has been envisioned as driven by the formation of an excitonic insulating phase. However, the role of structural and electronic instabilities on crystal symmetry breaking has yet to be disentangled. Meanwhile, the phase transition in its complementary material Ta2NiS5 does not show any experimental hints of an excitonic insulating phase. We present a microscopic investigation of the electronic and phononic effects involved in the structural phase transition in Ta2NiSe5 and Ta2NiS5 using extensive first-principles calculations. In both materials the crystal symmetries are broken by phonon instabilities, which in turn lead to changes in the electronic bandstructure also observed in the experiment. A total energy landscape analysis shows no tendency towards a purely electronic instability and we find that a sizeable lattice distortion is needed to open a bandgap. We conclude that an excitonic instability is not needed to explain the phase transition in both Ta2NiSe5 and Ta2NiS5.

Primary role of the structural phase transition in the strongly coupled structure and magnetism ofLa0.835Sr0.165MnO3single crystal

1998 ◽  
Vol 57 (12) ◽  
pp. R6775-R6778 ◽  
Author(s):  
K. V. Kamenev ◽  
G. J. McIntyre ◽  
D. McK Paul ◽  
M. R. Lees ◽  
G. Balakrishnan
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Primary Role ◽  
Strongly Coupled

Theoretical aspects in structural distortion and the electronic properties of lithium peroxide under high pressure

2018 ◽  
Vol 20 (14) ◽  
pp. 9488-9497 ◽  
Author(s):  
Pornmongkol Jimlim ◽  
Komsilp Kotmool ◽  
Udomsilp Pinsook ◽  
Suttichai Assabumrungrat ◽  
Rajeev Ahuja ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structural Phase ◽  
Structural Distortion ◽  
First Principles Calculations ◽  
Lithium Peroxide

The structural phase transition and electronic properties of Li2O2 under pressures up to 500 GPa have been investigated using first-principles calculations.

scholarly journals Role of thermal strain in the metal-insulator and structural phase transition of epitaxialVO2films

2016 ◽  
Vol 93 (18) ◽  
Author(s):  
V. Théry ◽  
A. Boulle ◽  
A. Crunteanu ◽  
J. C. Orlianges ◽  
A. Beaumont ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Thermal Strain ◽  
Metal Insulator

Structural phase transition, electronic, elastic, and vibrational properties of LiAl intermetallic compound: insights from first-principles calculations

2017 ◽  
Vol 95 (8) ◽  
pp. 691-698
Author(s):  
Y. Mogulkoc ◽  
Y.O. Ciftci ◽  
G. Surucu
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Structural Phase Transition ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Electronic Band

Using the first-principles calculations based on density functional theory (DFT), the structural, elastic, electronic, and vibrational properties of LiAl have been explored within the generalized gradient approximation (GGA) using the Vienna ab initio simulation package (VASP). The results demonstrate that LiAl compound is stable in the NaTl-type structure (B32) at ambient pressure, which is in good agreement with the experimental results and there is a structural phase transition from NaTl-type structure (B32) to CsCl-type structure (B2) at around 22.2 GPa pressure value. The pressure effects on the elastic properties have been discussed and the elastic property calculation indicates that the elastic instability could provide a phase transition driving force according to the variations relation of the elastic constant versus pressure. To gain further information about this, we also have investigated the other elastic parameters (i.e., Zener anisotropy factor, Poisson’s ratio, Young’s modulus, and isotropic shear modulus). The electronic band structure, total and partial density of states, phonon dispersion curves, and one-phonon density of states of B2 and B32 phases are also presented with results.

Thickness-dependent structural phase transition of strained SrRuO3ultrathin films: The role of octahedral tilt

2011 ◽  
Vol 84 (10) ◽  
Author(s):  
Seo Hyoung Chang ◽  
Young Jun Chang ◽  
S. Y. Jang ◽  
D. W. Jeong ◽  
C. U. Jung ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase

First-principles calculations for structural phase transition of LixFeS2

2008 ◽  
Vol 69 (5-6) ◽  
pp. 1353-1355 ◽  
Author(s):  
Atsushi Honda ◽  
Shin’ichi Higai ◽  
Nobuyuki Wada ◽  
Yukio Sakabe
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structural Phase ◽  
First Principles Calculations

Pressure-induced structural phase transition in Li4Ge

CrystEngComm ◽  
2018 ◽  
Vol 20 (39) ◽  
pp. 5949-5954 ◽  
Author(s):  
Chun-Mei Hao ◽  
Yunguo Li ◽  
Qiang Zhu ◽  
Xin-Yi Chen ◽  
Zhan-Xin Wang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
First Principles ◽  
Structure Prediction ◽  
Structural Phase ◽  
Crystal Structure Prediction ◽  
First Principles Calculations ◽  
Structural Dynamic

The structural, dynamic, elastic, and electronic properties of Li4Ge were investigated by means of evolutionary crystal structure prediction in conjunction with first-principles calculations.

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