Multiferroicity and hydrogen-bond ordering in (C2H5NH3)2CuCl4 featuring dominant ferromagnetic interactions

TL;DR

This study reveals that (C2H5NH3)2CuCl4 is a hybrid perovskite exhibiting multiferroicity, with ferroelectricity and ferromagnetic interactions, driven by hydrogen-bond ordering, and shows potential for multifunctional applications.

Contribution

It demonstrates the coexistence of ferroelectricity and ferromagnetic interactions in a hybrid perovskite, highlighting hydrogen-bond ordering as a key mechanism.

Findings

Large spontaneous polarization below 247 K

Color change associated with ferroelectric transition

Hydrogen-bond ordering influences multiferroic behavior

Abstract

We demonstrate that ethylammonium copper chloride, (C2H5NH3)2CuCl4, a member of the hybrid perovskite family is an electrically polar and magnetic compound with dielectric anomaly around the Curie point (247 K). We have found large spontaneous electric polarization below this point accompanied with a color change in the sample. The system is also ferroelectric, with large remnant polarization (37{\mu}C/cm2) that is comparable to classical ferroelectric compounds. The results are ascribed to hydrogen-bond ordering of the organic chains. The coexistence of ferroelectricity and dominant ferromagnetic interactions allows to relate the sample to a rare group of magnetic multiferroic compounds. In such hybrid perovskites the underlying hydrogen bonding of easily tunable organic building blocks in combination with the 3d transition-metal layers offers an emerging pathway to engineer multifuctional multiferroics.