Chemical structure of grain-boundary layer in SrTiO3and its segregation-induced transition: A continuum interface approach

doi:10.1088/1674-1056/27/6/060503

	Chemical structure of grain-boundary layer in SrTiO3and its segregation-induced transition: A continuum interface approach
	Gu, Hui
刊名	Chinese Physics B
	2018
卷号	27 期号:6
ISSN号	16741056
DOI	10.1088/1674-1056/27/6/060503
英文摘要	Grain-boundary (GB) structures are commonly imaged as discrete atomic columns, yet the chemical modifications are gradual and extend into the adjacent lattices, notably the space charge, hence the two-dimensional defects may also be treated as continuum changes to extended interfacial structure. This review presents a spatially-resolved analysis by electron energy-loss spectroscopy of the GB chemical structures in a series of SrTiO3 bicrystals and a ceramic, using analytical electron microscopy of the pre-Cs-correction era. It has identified and separated a transient layer at the model S5 grain-boundaries (GBs) with characteristic chemical bonding, extending the continuum interfacial approach to redefine the GB chemical structure. This GB layer has evolved under segregation of iron dopant, starting from subtle changes in local bonds until a clear transition into a distinctive GB chemistry with substantially increased titanium concentration confined within the GB layer in 3-unit cells, heavily strained, and with less strontium. Similar segregated GB layer turns into a titania-based amorphous film in SrTiO3 ceramic, hence reaching a more stable chemical structure in equilibrium with the intergranular Ti2O3 glass also. Space charge was not found by acceptor doping in both the strained S5 and amorphous GBs in SrTiO3 owing to the native transient nature of the GB layer that facilitates the transitions induced by Fe segregation into novel chemical structures subject to local and global equilibria. These GB transitions may add a new dimension into the structure-property relationship of the electronic materials. © 2018 Chinese Physical Society and IOP Publishing Ltd.
出版者	Institute of Physics Publishing
内容类型	期刊论文
源URL	[http://ir.sic.ac.cn/handle/331005/25136]
专题	中国科学院上海硅酸盐研究所
作者单位	School of Materials Science and Engineering, Materials Genome Institute, Shanghai University, Shanghai; 200444, China
推荐引用方式 GB/T 7714	Gu, Hui. Chemical structure of grain-boundary layer in SrTiO3and its segregation-induced transition: A continuum interface approach[J]. Chinese Physics B,2018,27(6).
APA	Gu, Hui.(2018).Chemical structure of grain-boundary layer in SrTiO3and its segregation-induced transition: A continuum interface approach.Chinese Physics B,27(6).
MLA	Gu, Hui."Chemical structure of grain-boundary layer in SrTiO3and its segregation-induced transition: A continuum interface approach".Chinese Physics B 27.6(2018).