Dielectric Spectroscopy on Organic Charge-Transfer Salts

TL;DR

This review summarizes the dielectric properties of organic charge-transfer salts, focusing on their electronic ferroelectricity and multiferroicity, based on literature data and new experimental results.

Contribution

It provides a comprehensive overview of dielectric behaviors in specific organic salts, highlighting recent findings on electronic ferroelectricity and multiferroicity.

Findings

Identification of dielectric response mechanisms

Observation of electronic ferroelectricity in (TMTTF)2X and BEDT-TTF salts

Discussion of multiferroic properties in these materials

Abstract

This Topical Review provides an overview of the dielectric properties of a variety of organic charge-transfer salts, based on both, data reported in literature and our own experimental results. Moreover, we discuss in detail the different processes that can contribute to the dielectric response of these materials. We concentrate on the family of the one-dimensional (TMTTF)2X systems and the two-dimensional BEDT-TTF-based charge-transfer salts, which in recent years have attracted considerable interest due to their often intriguing dielectric properties. We will mainly focus on the occurrence of electronic ferroelectricity in these systems, which also includes examples of multiferroicity.