Effect of methyl alcohol and nitric acid as an etchant on the motions of ferroelectric domains in Al-doped KNbO_3 single crystal

摘要

The domain structure of the single crystal KNbO_3 (KN) in the orthorhombic ferroelectrics phase at room temperature is investigated using optical and trinocular microscope. The cleavage face of ferroelectric Al-doped KN crystals was chemically etched using CH_3OH (Methanol). At room temperature and before etching, the 60°, 90° domains were observed on the crystal surface. A dislocation model is proposed to explain the nucleation and evaporation of the domain wall under the influence of the electric field, which can be used to study the changes in motion of ferroelectric domains. After etching with HNO_3 (Nitric acid) and applying an electric field, the 180° domains were observed.