Enhanced spontaneous polarization in superlattice-structured Bi4Ti3O12–BaBi4Ti4O15 single crystals

Abstract

Superlattice-structured ferroelectric single crystals composed of Bi4Ti3O12 (BiT) and BaBi4Ti4O15 (BBTi) have been reported to show a large spontaneous polarization as well as a sufficient insulating property. X-ray diffraction and transmission electron microscopy observations of the crystals revealed a superlattice structure with alternate stacking of the BiT and the BBTi layers. The Curie temperature (TC) of the BiT–BBTi crystals was about 540 °C, which was intermediate between those of BiT (675 °C) and BBTi (410 °C). Polarization measurements of the BiT–BBTi crystals along the a(b) axis demonstrate that the spontaneous polarization was 52μC∕cm2, which is larger than those of the BiT and BBTi crystals.