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arXiv · 1208.0633

Relaxor ferroelectricity induced by electron correlations in a molecular dimer Mott insulator

S. Iguchi·S. Sasaki·N. Yoneyama·H. Taniguchi·T. Nishizaki·T. Sasaki
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Abstract

We have investigated the dielectric response in an antiferromagnetic dimer-Mott insulator beta'-(BEDT-TTF)2ICl2 with square lattice, compared to a spin liquid candidate kappa-(BEDT-TTF)2Cu2(CN)3. Temperature dependence of the dielectric constant shows a peak structure obeying Curie-Weiss law with strong frequency dependence. We found an anisotropic ferroelectricity by pyrocurrent measurements, which suggests the charge disproportionation in a dimer. The ferroelectric actual charge freezing temperature is related to the antiferromagnetic interaction, which is expected to the charge-spin coupled degrees of freedom in the system.

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S. Iguchi, S. Sasaki, N. Yoneyama, H. Taniguchi, T. Nishizaki, T. Sasaki. 2013-01-29. Relaxor ferroelectricity induced by electron correlations in a molecular dimer Mott insulator. https://doi.org/10.1103/physrevb.87.075107

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