Hierarchical domain structures associated with oxygen octahedra tilting patterns in lead-free (Bi1/2Na1/2)TiO3.

Authors :: Hu, Dongli
Fan, Zhongming
Sawyer, William
Henderson, Mitchell
Luo, Duan
Liu, Xiaoming
Gu, Hui
Tan, Xiaoli
Wen, Jianguo
Source :: Nanotechnology; 2/12/2023, Vol. 34 Issue 7, p1-9, 9p
Publication Year :: 2023
Abstract: Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi<subscript>1/2</subscript>Na<subscript>1/2</subscript>)TiO<subscript>3</subscript> ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the 'orientation-domain' is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the 'meso-chemical-domain' occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO<subscript>3</subscript> perovskite structure, and the 'nano-cluster-region' runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi<subscript>1/2</subscript>Na<subscript>1/2</subscript>)TiO<subscript>3</subscript> is also discussed. [ABSTRACT FROM AUTHOR]

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