Formation of self-assembled micro- and nano-domain structures in uniaxial ferroelectrics

International Conference "Structural and Phase Transformations in Materials: Theory, Computer Modelling and Experiment"

材料科学;计算机科学

Shur, V Ya^1 ; Shur, A.G.^1 ; Akhmatkhanov, A.R.^1

School of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg

620000, Russia^1

关键词: Artificial dielectric layers;    Domain structure;    External electric field;    Nucleation process;    Self-assembled domains;    Shape instability;    Stoichiometric lithium tantalates;    Switching conditions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/192/1/012006/pdf
DOI  :  10.1088/1757-899X/192/1/012006

来源: IOP

【 摘 要 】

We present the experimental study of appearance of domain wall shape instabilities and self-assembled domain structures in uniaxial ferroelectrics lithium niobate and lithium tantalate covered by artificial dielectric layer. The domain structure evolution has been considered as a manifestation of nucleation processes similar to the first order phase transformation. The necessary conditions for formation of self-assembled domain structures including the highly non-equilibrium switching conditions and stability of concave angles were proposed. The formation of the self-assembled domain shape instabilities under application of the uniform external electric field during switching (domain growth) and backswitching (domain shrinkage) has been studied experimentally with these conditions fulfilled. The formation of the bumps at the vortexes of hexagon domain for diameter above 3 - 5 μm with subsequent oriented growth was obtained in stoichiometric lithium tantalate. The formation of quasi-regular fish-bone domain structure has been revealed during spontaneous backswitching in Mg doped lithium niobate. The resulted structure consisted of the narrow residual domains with width from 200 to 500 nm appeared as a result of finger growth to the center of hexagon domain. The obtained decreasing of the number of the residual domains during growth has been attributed to strong electrostatic interaction of domain walls.