Separation of Charge Instability and Lattice Symmetry Breaking in an Organic Ferroelectric

Abstract

We investigate the charge and lattice states in a quasi-one-dimensional organic ferroelectric material, TTF-QCl${}_4$, under pressures of up to 35 kbar by nuclear quadrupole resonance experiments. The results reveal a global pressure-temperature phase diagram, which spans the electronic and ionic regimes of ferroelectric transitions, which have so far been studied separately, in a single material. The revealed phase diagram clearly shows that the charge-transfer instability and the lattice symmetry breaking, which coincide in the electronic ferroelectric regime at low pressures, bifurcate at a certain pressure, leading to the conventional ferroelectric regime. The present results reveal that the crossover from electronic to ionic ferroelectricity occurs through the separation of charge and lattice instabilities.

arXiv comment7 pages 5 figures (including supplementary material)

References in corpus (6)

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Cited by in corpus (5)

• Magnetic excitations in an ionic spin-chain system with a non-magnetic ferroelectric instability
• Fate of a soliton matter upon symmetry-breaking ferroelectric order
• Enhanced lattice fluctuations prior to a nonmagnetic ferroelectric order in an ionic spin-chain system
• Experimental Verification of Charge Soliton Excitations in the Ionic Mott-Peierls Ferroelectric, TTF-CA
• Quantum transport of topological spin solitonsin a one-dimensional organic ferroelectric