In this paper,Na2W4O13 nanosheets were prepared by thermal oxidation method and characterized by scanning transmission electron microscopy at the atomic scale.Typical twin structures were observed in most samples.The formation of domain structure in Na2W4O13 was analyzed by group theory.Nine possible domain structures were predicted.Among them,the type3 mirror twin is consistent with the(100)twin with the orientation relationship of[010]//[0(1)0]T and(100)//(100)T.Additionally,the electron beam irradiation on single crystalline and twinning-structure nanomaterials was studied.The phase-transition from triclinic-structure Na2W4O13 to cubic-phase NaxWO3(x＜0.5)occurred in both types of samples.The samples with twinning structure showed the nucleation of point defect caused by lattice mismatch between twin variant and substrate.Our result shed light on the microstructure in layered Na2W4O13 materials,which may facilitate the basic understanding of the structure-property interplay in tungsten bronzes.
关键词
钠钨青铜Na2W4O13/过渡金属层状氧化物/取向畴/群论/透射电子显微学
Key words
sodium tungsten bronze Na2W4O13/transition metal layer oxide/orientation domain/group theory/transmission electron microscope
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