Single-water-dipole-layer-driven Reversible Charge Order Transition in 1T-TaS2

We studied the charge order transition of LiMn 2 O 4 by means of anelastic spectroscopy, measuring the Young's modulus, E, and the elastic energy loss function, Q-1. Our measurements confirm the occurrence of a phase transition at 296 K on cooling, showing a large hysteresis on heating. Around the transition temperature the Young's modulus shape reveals that there is at least one elastic constant, possibly c44, decreasing lowering the temperature. Moreover the anelastic spectroscopy results confirm that the transformation is characterised by the coexistence of two phases in a narrow temperature range. The time constant of the transformation of the cubic into the orthorhombic phase sharply decreases lowering T from 296 to 290 K and then increases on further cooling to 289 K. The strong decrease of the time constant around 290 K can be related to the reduction of the c44 elastic constant.

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Electronic properties and charge order transition in (TMTTF)2X under c *-direction pressure

physica status solidi (c) ◽

10.1002/pssc.201100628 ◽

2012 ◽

Vol 9 (5) ◽

pp. 1161-1163 ◽

Cited By ~ 1

Author(s):

Mitsuharu Nagasawa ◽

Tokiko Nagasawa ◽

Koichi Ichimura ◽

Kazushige Nomura

Keyword(s):

Electronic Properties ◽

Charge Order ◽

Order Transition

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Anisotropic pressure effects on the charge order transition of (TMTTF)2X

Physica B Condensed Matter ◽

10.1016/j.physb.2010.01.091 ◽

2010 ◽

Vol 405 (11) ◽

pp. S113-S115 ◽

Cited By ~ 2

Author(s):

M. Nagasawa ◽

T. Nagasawa ◽

K. Ichimura ◽

K. Nomura

Keyword(s):

Charge Order ◽

Order Transition ◽

Pressure Effects ◽

Anisotropic Pressure

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Optical Conductivity on Charge Order Transition in Organic Dirac Electron System α-(BEDT-TTF)2I3

10.20944/preprints201802.0159.v1 ◽

2018 ◽

Author(s):

Daigo Ohki ◽

Genki Matsuno ◽

Yukiko Omori ◽

Akito Kobayashi

Keyword(s):

Optical Conductivity ◽

Mean Field Theory ◽

Mean Field ◽

Charge Order ◽

Electron System ◽

Order Transition ◽

Peak Structure ◽

Dirac Electron ◽

The Mean ◽

Valence Bands

The optical conductivity in the charge order phase is calculated in the extended Hubbard model describing an organic Dirac electron system α-(BEDT-TTF)2I3 using the mean field theory and the Nakano-Kubo formula. A peak structure due to interband excitation being characteristic in two-dimensional Dirac electron system is found above the charge order gap. It is shown that the peak structure originates from the Van Hove singularities of the conduction and valence bands, where those singularities are located at a saddle point between two Dirac cones in momentum space. The frequency of the peak structure exhibits drastic change in the vicinity of the charge order transition.

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