^{1,a)}, De’an Liu

^{1}, Jianfeng Sun

^{1}, Aimin Yan

^{1}, Yu Zhou

^{1}, Zhu Luan

^{1}, Enwen Dai

^{1}, Liren Liu

^{1}and Weijuan Qu

^{2}

### Abstract

The phase mapping of domain kinetics under the uniform steady-state electric field is achieved and investigated in the crystals by digital holographic interferometry. We obtained the sequences of reconstructed three-dimensional and two-dimensional wave-field phase distributions during the electric poling in the congruent and near stoichiometric crystals. The phase mapping of individual domain nucleation and growth in the two crystals are obtained. It is found that both longitudinal and lateral domain growths are not linear during the electric poling. The phase mapping of domain wall motions in the two crystals is also obtained. Both the phase relaxation and the pinning-depinning mechanism are observed during the domain wall motion. The residual phase distribution is observed after the high-speed domain wall motion. The corresponding analyses and discussions are proposed to explain the phenomena.

This work was supported by Chinese Academy of Sciences, the National Natural Science Foundation of China (Grant No.60708018), and the Ministry of Science and Technology of China (Grant No. 2007AA01Z298)

I. INTRODUCTION

II. EXPERIMENTAL SCHEME

III. INDIVIDUAL DOMAIN NUCLEATION AND GROWTH

A. The phase mapping of individual domain nucleation and growth

B. The longitudinal and lateral growths

C. Analyses and discussions

IV. 180° DOMAIN WALL MOTION

A. The phase relaxation during 180° domain wall motion

B. The pinning-depinning mechanism during domain wall motion

C. The residual phase after high-speed domain wall motion

V. CONCLUSIONS

### Key Topics

- Domain walls
- 53.0
- Crystal growth
- 23.0
- Nucleation
- 23.0
- Point defects
- 19.0
- Crystal stoichiometry
- 18.0

## Figures

The schematic diagram of the measurement principle by digital holographic interferometry. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. The uniform external electric field is applied and the different phase retardations are obtained as and , respectively. is the longitudinal dimension of reversed domain and is the thickness of the crystal wafer.

The schematic diagram of the measurement principle by digital holographic interferometry. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. The uniform external electric field is applied and the different phase retardations are obtained as and , respectively. is the longitudinal dimension of reversed domain and is the thickness of the crystal wafer.

The schematic diagram of experimental device within a Mach–Zehnder interferometer. BS: beam splitter; SF: spatial filter; CL: collimating lens; L: lens; and CCD: charge coupled device.

The schematic diagram of experimental device within a Mach–Zehnder interferometer. BS: beam splitter; SF: spatial filter; CL: collimating lens; L: lens; and CCD: charge coupled device.

The selected sequence of reconstructed three-dimensional wave-field phase distributions during the individual domain nucleation and growth in the congruent crystal. The eight frames labeled as 3(a)–3(h) show the nucleation and growth of individual 180° domain microstructure in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 2, (b) 4, (c) 10, (d) 14, (e) 16, (f) 20, (g) 26, and (h) 30. The polarization axis is along the axis.

The selected sequence of reconstructed three-dimensional wave-field phase distributions during the individual domain nucleation and growth in the congruent crystal. The eight frames labeled as 3(a)–3(h) show the nucleation and growth of individual 180° domain microstructure in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 2, (b) 4, (c) 10, (d) 14, (e) 16, (f) 20, (g) 26, and (h) 30. The polarization axis is along the axis.

The sequence of reconstructed two-dimensional wave-field phase distributions during the individual domain nucleation and growth in the near stoichiometric crystal. The eight frames labeled as 6(a)–6(h) show the nucleation and growth of individual 180° domain microstructure in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 3, (b) 4, (c) 6, (d) 10, (e) 12, (f) 13, (g) 14, and (h) 17. The polarization axes are normal to the image plane.

The sequence of reconstructed two-dimensional wave-field phase distributions during the individual domain nucleation and growth in the near stoichiometric crystal. The eight frames labeled as 6(a)–6(h) show the nucleation and growth of individual 180° domain microstructure in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 3, (b) 4, (c) 6, (d) 10, (e) 12, (f) 13, (g) 14, and (h) 17. The polarization axes are normal to the image plane.

The diagram of the domain dimension variation in the longitudinal direction and the lateral direction with the increase of poling time in the congruent crystal.

The diagram of the domain dimension variation in the longitudinal direction and the lateral direction with the increase of poling time in the congruent crystal.

The diagram of the domain dimension variation in the longitudinal direction and the lateral direction with the increase in poling time in the near stoichiometric crystal.

The diagram of the domain dimension variation in the longitudinal direction and the lateral direction with the increase in poling time in the near stoichiometric crystal.

The schematic diagram of individual domain nucleation and growth. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. : the applied electric field; : the longitudinal dimension of reversed domain; and : the lateral dimension of reversed domain.

The schematic diagram of individual domain nucleation and growth. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. : the applied electric field; : the longitudinal dimension of reversed domain; and : the lateral dimension of reversed domain.

The selected sequence of reconstructed three-dimensional wave-field phase distributions during the domain wall motion in the congruent crystal. The six frames labeled as 8(a)–8(f) show the 180° domain wall motion in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 12, (b) 17, (c) 19, (d) 29, (e) 31, (f) 38. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. The ridge-shape phase distributions appear adjacent to the polarization gradient at the 180° domain walls, which are indicated as ridge- and ridge-, respectively, by the arrows from Figs. 8(a)–8(f).

The selected sequence of reconstructed three-dimensional wave-field phase distributions during the domain wall motion in the congruent crystal. The six frames labeled as 8(a)–8(f) show the 180° domain wall motion in the wafer at different times after the application of the steady voltage (at ). The times (in seconds) corresponding to each frame are (a) 12, (b) 17, (c) 19, (d) 29, (e) 31, (f) 38. The two antiparallel domain states are presented as virginal state and reversed state , respectively. The spontaneous polarizations are labeled as and , respectively. The ridge-shape phase distributions appear adjacent to the polarization gradient at the 180° domain walls, which are indicated as ridge- and ridge-, respectively, by the arrows from Figs. 8(a)–8(f).

The selected sequence of reconstructed two-dimensional wave-field phase distributions after the high-speed domain wall motion in the congruent crystal. (a) corresponds to after the application of the steady voltage (at ), and (b) is 1 s apart from that. The direction of domain motion is indicated by the arrow. The original position of domain boundary is indicated by the dashed line in (a). The new position of domain boundary is indicated by the dashed line in (b).

The selected sequence of reconstructed two-dimensional wave-field phase distributions after the high-speed domain wall motion in the congruent crystal. (a) corresponds to after the application of the steady voltage (at ), and (b) is 1 s apart from that. The direction of domain motion is indicated by the arrow. The original position of domain boundary is indicated by the dashed line in (a). The new position of domain boundary is indicated by the dashed line in (b).

(a) The scanning line across the antiparallel domain along the axis. (b) The three-dimensional wave-field phase distributions after the high-speed domain wall motion in the congruent crystal. The residual phase region is indicated by the dashed line.

(a) The scanning line across the antiparallel domain along the axis. (b) The three-dimensional wave-field phase distributions after the high-speed domain wall motion in the congruent crystal. The residual phase region is indicated by the dashed line.

Article metrics loading...

Full text loading...

Commenting has been disabled for this content