Non-180° domains formation mechanism in LiTaO3 grains of an Al2O3/LiTaO3 composite

Abstract High density (>99.5%) Al 2 O 3 /LiTaO 3 (ALT) composite was obtained by hot pressing at 1300 °C/25 MPa in nitrogen atmosphere. The microstructure, which included a domain structure in LiTaO 3 grains, was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Most of the domains observed in LiTaO 3 grains of the Al 2 O 3 /LiTaO 3 (ALT) composites belong to a non-180° type domain, which cannot exist in LiTaO 3 single crystals. This non-symmetry domain microstructure belongs to ferroelectric twinning with { 1 ¯ 0 1 2 } twin composition plane. The non-180° domains formation mechanism was proposed.