Domain switching mechanism of orthorhombic-tetragonal coexistence (Li,K,Na)NbO₃ ceramics

Herein we proposed an approach to quantitatively evaluate the individual contribution of orthorhombic and tetragonal phase in the polymorphic phase transition (PPT) region of Li modified (K,Na)NbO₃ during the poling process. Through investigating the feature of domain switching in orthorhombic and tetragonal phase, it found that the essence for the switching of polarization vectors 〈110〉 in orthorhombic phase and 〈001〉 in tetragonal phase was tiny ion displacement. With the increase of Li content the volume ratio of tetragonal phase in the coexistence phase at room temperature went up as well as the value of ion displacement and X-ray diffraction results could clearly elaborate the validity of the above statement.