Exciting low-field dielectric tunability in clamshell

The dielectric properties and dielectric tunability of the nacreous part of the clamshell were investigated. Microstructure characterizations reveal that the sample shows a “brick-and-mortar” structure composed of aragonitic CaCO3 regions and bimacromolecule regions separated by transition regions consisting of crystalline particles surrounded by amorphous area. A ferroelectric-like dielectric tunability behavior was observed and an exciting dielectric tunability of 79% was achieved at 400 °C and 500 Hz within a small field increment of 34 V/cm. Such a low field scale for dielectric tunability near 80% rivals all known tunable dielectrics. Both thermally and electrically activated hopping motion of oxygen vacancies in the multilayered structures of the clamshell leads to the exciting low-field dielectric tunability. Our results dramatically expand the dielectric tunable materials and offer a facile way to achieve superior dielectric tunability in bio-multilayered materials.