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Title: Domain wall kinetics of lithium niobate single crystals near the hexagonal corner

A mesospheric approach based on a simple microscopic 2D Ising model in a hexagonal lattice plane is proposed to explain macroscopic “asymmetric in-out domain wall motion” observation in the (0001) plane of MgO-doped stoichiometric lithium niobate. Under application of an electric field that was higher than the conventional coercive field (E{sub c}) to the ferroelectric crystal, a natural hexagonal domain was obtained with walls that were parallel to the Y-axis of the crystal. When a fraction of the coercive field of around 0.1E{sub c} is applied in the reverse direction, this hexagonal domain is shrunk (moved inward) from the corner site into a shape with a corner angle of around 150° and 15° wall slopes to the Y-axis. A flipped electric field of 0.15E{sub c} is then applied to recover the natural hexagonal shape, and the 150° corner shape changes into a flat wall with 30° slope (moved outward). The differences in corner domain shapes between inward and outward domain motion were analyzed theoretically in terms of corner and wall site energies, which are described using the domain corner angle and wall slope with respect to the crystal Y-axis, respectively. In the inward domain wall motion case, the energy levelsmore » of the evolving 150° domain corner and 15° slope walls are most competitive, and could co-exist. In the outward case, the energy levels of corners with angles >180° are highly stable when compared with the possible domain walls; only a flat wall with 30° slope to the Y-axis is possible during outward motion.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)
  2. (Korea, Republic of)
  3. Advanced Photonics Research Institute, GIST, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)
  4. National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan)
  5. Department of Biomedical Engineering, School of Medicine, Pusan National University, Busan 602-739 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22395720
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ASYMMETRY; COERCIVE FORCE; COMPARATIVE EVALUATIONS; DOMAIN STRUCTURE; DOPED MATERIALS; ELECTRIC FIELDS; ENERGY LEVELS; FERROELECTRIC MATERIALS; HEXAGONAL LATTICES; ISING MODEL; LITHIUM COMPOUNDS; MAGNESIUM OXIDES; MONOCRYSTALS; NIOBATES; STOICHIOMETRY