Structural Phase Transition from Fluorite to Orthorhombic FeSi2 by Tight Binding Molecular Dynamics

1995 ◽  
Vol 408 ◽  
Author(s):  
Leo Miglio ◽  
Massimo Celino ◽  
Valeria Meregalli ◽  
Francesca Tavazza
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Density Of States ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Tight Binding ◽  
Dynamics Simulation ◽  
Fluorite Phase ◽  
Electronic Density ◽  
Jahn Teller

AbstractIn this paper we report a molecular dynamics simulation at constant pressure and constant temperature of the structural phase transition occurring in epitaxial FeSi2 from the fluorite phase (metallic and pseudomorphic) to orthorhombic one (semiconductor and bulk stable). The evolution of the electronic density of states is carefully monitored during the transformation and we can show that the Jahn-Teller coupling between the density of states at the Fermi level and the lattice deformation drives the metal-semiconductor transition.

Pressure-induced Structural Phase Transition of Carbon Nanotubes into New Nanostructured Carbon Solids

2009 ◽  
Vol 1204 ◽  
Author(s):  
Masahiro Sakurai ◽  
Susumu Saito
Keyword(s):  
Phase Transition ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Structural Phase Transition ◽  
Density Functional ◽  
Local Density ◽  
Structural Phase ◽  
Tight Binding ◽  
Dynamics Simulation ◽  
Nanotube Bundles

AbstractWe study pressure-induced structural phase transition of carbon nanotubes using the constant-pressure tight-binding molecular-dynamics simulation. The systems studied are nanotube bundles composed of (6,6) armchair nanotube and/or (7,4) chiral nanotube, which are reported to be the nanotubes relatively abundant in experimentally purified sample. We find that the nanotube bundles transforms into a new phase that consist of graphitic ribbons and diamond blocks, “graphitic nanoribbon solid”. It is also found that sp3-rich phases obtained from the armchair nanotubes possess an anisotropic network and have high hardness which is comparable to that of cubic diamond. In the case of the bundles containing chiral nanotubes, on the other hand, amorphous diamond phase is obtained. Based on the local-density approximation in the density-functional theory, we also investigate the energetics and electronic structure of some of new carbon phases obtained in the molecular-dynamics study.

Cooperative Pseudo Jahn-Teller Effect as Microscopic Mechanism of (OMT)-(LTT) Structural Phase Transition in La2−xBaxCuO4Superconductors

1992 ◽  
Vol 291 ◽  
Author(s):  
Michael D. Kaplan
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Electronic States ◽  
Teller Effect ◽  
Excited Electronic States ◽  
Microscopic Mechanism ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Local Distortions

ABSTRACTA microscopic mechanism for the structural phase transition from the orthorhombic mediate temperature (OMT) phase into the low temperature tetragonal (LTT) one is suggested on the basis of the cooperative pseudo Jahn-Teller effect. The local distortions mixing the ground and the first excited electronic states are ordered antiferrodistortively and are connected in part, with the oxygen octahedra rotations around the [100] axis. The results are in agreement, with the neutron scattering experiments data.

scholarly journals Molecular dynamics and structural phase transition in C60nanowhiskers

2009 ◽  
Vol 159 ◽  
pp. 012022 ◽  
Author(s):  
Hideaki Kitazawa ◽  
Kenjiro Hashi ◽  
Tuerxun Wuernisha ◽  
Kayoko Hotta ◽  
Cherry L Ringor ◽  
...  
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Structural Phase Transition ◽  
Structural Phase
Sign in / Sign up

Export Citation Format

Share Document