Ferroelectric phase transition, ionicity condensation, and multicriticality in charge transfer organic complexes

Abstract

To elucidate a novel pressure-temperature phase diagram of the quasi-one-dimensional mixed-stack charge-transfer (CT) complex TTF-CA, we study the quasi-one-dimensional spin-1 Blume-Emery-Griffith (BEG) model. In addition to the local charge transfer energy and the inter-stack polar (dipole-dipole) interaction, we take account of the inter-stack electrostriction effect. Using the self-consistent chain-mean-field theory, where the intra-stack degrees of freedom are exactly treated by the transfer-matrix method, we reproduce the gas-liquid-solid like phase diagram corresponding to the neutral (N), paraelectric ionic (I${}_{\mathrm{para}}$), and ferroelectric ionic (I${}_{\mathrm{ferro}}$) phases, respectively. We also give an explanation on the experimentally observed multicritical behavior and concomitant discontinuous inter-stack lattice contraction in TTF-CA.

6 pages, 5 figures

References in corpus (1)

• Crucial Effects of Intramolecular Charge Distribution on the Neutral-Ionic Transition of Tetrathiafulvalene - p-Chloranil

Cited by in corpus (8)

• Theory of Photoinduced Phase Transitions
• Separation of Charge Instability and Lattice Symmetry Breaking in an Organic Ferroelectric
• Interchain coupling effects on photoinduced phase transitions between neutral and ionic phases in an extended Hubbard model with alternating potentials and an electron-lattice coupling
• Phase Transition in a One-Dimensional Extended Peierls-Hubbard Model with a Pulse of Oscillating Electric Field: I. Threshold Behavior in Ionic-to-Neutral Transition
• Phase Competition, Solitons, and Domain Walls in Neutral-Ionic Transition Systems
• Effects of Lattice and Molecular Phonons on Photoinduced Neutral-to-Ionic Transition Dynamics in Tetrathiafulvalene-$p$-Chloranil
• Fate of a soliton matter upon symmetry-breaking ferroelectric order
• Enhanced coherent dynamics near a transition between neutral quantum-paraelectric and ionic ferroelectric phases in the quantum Blume-Emery-Griffiths model