Insitu observation of the motion of ferroelectric domain walls in Bi4Ti3O12 single crystals

• Published in: Journal of applied crystallography Vol. 49; no. 5; pp. 1645 - 1652
• Main Authors: Ye, Wanneng, Tang, Lingli, Lu, Chaojing, Li, Huabing, Zhou, Yichun
• Format: Journal Article
• Language: English; Japanese
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01.10.2016
• Subjects: Bi4Ti3O12; domain wall motion; ferroelectrics; optical microscopy; transmission electron microscopy
• ISSN: 1600-5767; 1600-5767
• DOI: 10.1107/S1600576716012267

Five types of ferroelectric domain walls (DWs) are present in Bi4Ti3O12 single crystals (Ye et al., 2015). Here their motion was investigated in situ using transmission electron microscopy and optical microscopy. The motion of P(a)‐90° DWs, P(a)‐180° DWs and P(c)‐180° DWs was observed through electron beam poling in a transmission electron microscope. The growth of new Ps(a)‐180° nanodomains was frequently seen and they tended to nucleate at preexisting Ps(a)‐90° DWs. Irregularly curved P(c)‐180° DWs exhibit the highest mobility, while migration over a short range occurs occasionally for faceted Ps(a)‐90° DWs. In addition, the motion of Ps(a)‐90° DWs and the growth/annihilation of new needle‐like Ps(a)‐90° domains in a 20 µm‐thick crystal were observed under an external electric field on an optical microscope. Most of the new needle‐like Ps(a)‐90° domains nucleate at preexisting Ps(a)‐90° DWs and the former are much smaller than the latter. This is very similar to the situation for Ps(a)‐180° domain switching induced by electron beam poling in a transmission electron microscope. Our observations suggest the energy hierarchy for different domains of Ps(c)‐180° ≤ Ps(a)‐180° ≤ Ps(a)‐90° ≤ new needle‐like Ps(a)‐90° in ferroelectric Bi4Ti3O12. The motion of ferroelectric domain walls (DWs) in a ferroelectric Bi4Ti3O12 single crystal was observed in situ under electron‐beam irradiation in a transmission electron microscope. The migration of Ps(a)‐90° DWs and the growth/annihilation of new needle‐like Ps(a)‐90° domains in a 20 µm‐thick crystal were observed insitu under an applied electric field on a optical microscope.