当前位置：
X-MOL 学术
›
Acta Crystallogr. A Found. Adv.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Multiwavelength anomalous X-ray diffraction for combined imaging of atomic displacement and strain
Acta Crystallographica Section A: Foundations and Advances ( IF 1.9 ) Pub Date : 2021-06-21 , DOI: 10.1107/s2053273321004976 Anatoly G Shabalin 1 , Oleg G Shpyrko 1
Acta Crystallographica Section A: Foundations and Advances ( IF 1.9 ) Pub Date : 2021-06-21 , DOI: 10.1107/s2053273321004976 Anatoly G Shabalin 1 , Oleg G Shpyrko 1
Affiliation
|
The X-ray Bragg coherent diffractive imaging (CDI) technique assumes that the structure factor holds constant over the measured crystal. This approximation breaks down for materials exhibiting variations in the unit-cell configuration, such as piezo- and ferroelectrics. In that case, the strain field cannot be reliably determined from the reconstruction because the lattice deformation and the structure factor contribute concomitantly. Proposed here is a solution to this problem achieved by combining Bragg CDI and the multiwavelength anomalous diffraction approach that measures a Friedel pair of reflections at two different photon energies near an absorption edge. Comparing the obtained reconstructions with a parametric model that includes calculating the scattering amplitude as a function of wavelength and the unit-cell configuration, the contributions of the lattice deformation and the structure factor are separated. Simulations of the ferroelectric material BaTiO3 demonstrate the possibility of simultaneous probing of the strain and displacement of the Ti atoms. The proposed method opens up an opportunity to apply coherent X-ray diffraction for nanoscale-resolved 3D mapping of polarization domains in micro- and nanocrystals.
中文翻译：
用于原子位移和应变组合成像的多波长异常 X 射线衍射
X 射线布拉格相干衍射成像 (CDI) 技术假设结构因子在被测晶体上保持恒定。对于在单元结构中表现出变化的材料，例如压电和铁电体，这种近似会失效。在这种情况下，由于晶格变形和结构因子同时起作用，因此无法从重建中可靠地确定应变场。这里提出的是通过结合布拉格 CDI 和多波长反常衍射方法来解决这个问题的方法，该方法测量吸收边缘附近两个不同光子能量处的弗里德尔反射对。将获得的重建与参数模型进行比较，该模型包括计算散射幅度作为波长和晶胞配置的函数，晶格变形和结构因子的贡献是分开的。铁电材料 BaTiO 的模拟图3展示了同时探测Ti原子的应变和位移的可能性。所提出的方法为将相干 X 射线衍射应用于微米和纳米晶体中偏振域的纳米级分辨 3D 映射开辟了机会。
更新日期：2021-07-01
中文翻译：
用于原子位移和应变组合成像的多波长异常 X 射线衍射
X 射线布拉格相干衍射成像 (CDI) 技术假设结构因子在被测晶体上保持恒定。对于在单元结构中表现出变化的材料，例如压电和铁电体，这种近似会失效。在这种情况下，由于晶格变形和结构因子同时起作用，因此无法从重建中可靠地确定应变场。这里提出的是通过结合布拉格 CDI 和多波长反常衍射方法来解决这个问题的方法，该方法测量吸收边缘附近两个不同光子能量处的弗里德尔反射对。将获得的重建与参数模型进行比较，该模型包括计算散射幅度作为波长和晶胞配置的函数，晶格变形和结构因子的贡献是分开的。铁电材料 BaTiO 的模拟图3展示了同时探测Ti原子的应变和位移的可能性。所提出的方法为将相干 X 射线衍射应用于微米和纳米晶体中偏振域的纳米级分辨 3D 映射开辟了机会。
京公网安备 11010802027423号