Evolution of ferroelectricity in tetrathiafulvalene-p-chloranil as a function of pressure and temperature
Armin Dengl1, Rebecca Beyer1, Tobias Peterseim1
11. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
Abstract:
The neutral-to-ionic phase transition in the mixed-stack charge-transfer complex tetrathiafulvalene-p-chloranil (TTF-CA) has been studied by pressure-dependent infrared spectroscopy up to p = 11 kbar and down to low temperatures, T = 10 K. By tracking the C=O antisymmetric stretching mode of CA molecules, we accurately determine the ionicity of TTF-CA in the pressure-temperature phase diagram. At any point, the TTF-CA crystal bears only a single ionicity; there is no coexistence region or an exotic high-pressure phase. Our findings shed new light on the role of electron-phonon interaction in the neutral-ionic transition.
More Related Videos
Related Concept Videos
Phase Diagram
pV-Diagrams
Clausius-Clapeyron Equation
Le Chatelier's Principle: Changing Volume (Pressure)
Ferromagnetism
Phase Diagrams


