Mads Carlsen, Florencia Malamud, Peter Modregger, Anna Wildeis, Markus Hartmann, Robert Brandt, Andreas Menzel, Marianne Liebi
{"title":"Texture tomography with high angular resolution utilizing sparsity","authors":"Mads Carlsen, Florencia Malamud, Peter Modregger, Anna Wildeis, Markus Hartmann, Robert Brandt, Andreas Menzel, Marianne Liebi","doi":"10.1107/S1600576725001426","DOIUrl":"https://doi.org/10.1107/S1600576725001426","url":null,"abstract":"<p>We demonstrate an approach to the reconstruction of scanning probe X-ray diffraction tomography data with anisotropic polycrystalline samples. The method involves reconstructing a voxel map containing an orientation distribution function in each voxel of a bulk 3D sample. By choosing a particular kind of basis functions, we can effectively utilize non-negativity in orientation space for samples with sparse texture. This enables us to achieve stable solutions at high angular resolutions where the problem would otherwise be underdetermined. This method differs from established approaches by not relying on a peak-finding step. It is therefore applicable to sample systems consisting of small and highly mosaic crystalline domains that are not handled well by these methods. We demonstrate the new approach using data from a shot-peened martensite sample where we are able to map the twinning microstructure in the interior of a bulk sample without resolving the individual lattice domains. We also demonstrate the approach on a piece of gastropod shell with a mosaic microstructure. The results suggest that, by utilizing the sparsity of the texture, the experiment can be carried out using only a single rotation axis, unlike previous demonstrations of texture and tensor tomography.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"58 2","pages":"484-494"},"PeriodicalIF":5.2,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chemical units of binary solid-solution alloys directly derived from short-range-order parameters","authors":"Zhuang Li, DanDan Dong, Qing Wang, Chuang Dong","doi":"10.1107/S1600576725001359","DOIUrl":"https://doi.org/10.1107/S1600576725001359","url":null,"abstract":"<p>Short-range ordering is a typical structural characteristic of solid solutions. According to our cluster-plus-glue-atom model, the chemical unit of a solid solution covers a nearest-neighbor cluster and a few next-nearest-neighbor glue atoms, [cluster](glue atoms). However, the determination of the number of atoms located in these two shells requires complex calculations. The present work provides a simple method to obtain the chemical unit in a direct manner using Cowley's short-range-order parameters α<sub>1</sub> and α<sub>2</sub>, by graphically illustrating the relationship between the total number of glue atoms and the ratio of atomic radii. For example, according to this graphical illustration, the Cu<sub>68.9</sub>Zn<sub>31.1</sub> alloy should have four glue atoms. Using its measured α<sub>1</sub> = −0.137 and α<sub>2</sub> = 0.149, a new form of chemical unit is obtained, [Zn–Cu<sub>9.40</sub>Zn<sub>2.60</sub>]Zn<sub>1.65</sub>Cu<sub>2.35</sub>, which is further simplified into integer forms of [Zn–Cu<sub>10</sub>Zn<sub>2</sub>]Zn<sub>3</sub>Cu<sub>1</sub> = Cu<sub>11</sub>Zn<sub>6</sub> or [Zn–Cu<sub>9</sub>Zn<sub>3</sub>]Zn<sub>1</sub>Cu<sub>3</sub> = Cu<sub>12</sub>Zn<sub>5</sub>, explaining the cartridge brasses C27000 (65Cu–35Zn) and C26000 (70Cu–30Zn), respectively. This provides a new way of understanding the composition of industrial alloys from their atomic origins and offers a new alloy design strategy.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"58 2","pages":"429-434"},"PeriodicalIF":5.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fourier modal method for calculating neutron scattering from surface-relief and bulk diffraction gratings","authors":"Maxim Zakharov, Alexander Frank, German Kulin","doi":"10.1107/S1600576725000615","DOIUrl":"https://doi.org/10.1107/S1600576725000615","url":null,"abstract":"<p>We report a rigorous method for calculating the interaction of neutron waves with a periodic potential structure. In earlier work, several assumptions and simplifications were used in methods describing the diffraction of neutron waves from relief gratings. The approach presented here is based on the Fourier modal method widely used in electromagnetic wave optics, which has been adapted for the case of a neutron wave. It allows consideration of the mutual influence of waves of different diffraction orders and has no restrictions on either the range of energies under consideration or the shape of the structure profile. The developed theory makes it possible to accurately interpret the results of experiments on neutron scattering on surface-relief and bulk periodic structures.</p>","PeriodicalId":48737,"journal":{"name":"Journal of Applied Crystallography","volume":"58 2","pages":"412-418"},"PeriodicalIF":5.2,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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