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DDC: 540 × Subject: Defects ×

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    Erratum: Exploring the 3D structure and defects of a self-assembled gold mesocrystal by coherent X-ray diffraction imaging (Nanoscale (2021) DOI: 10.1039/D1NR01806J)
    (Cambridge : RSC Publ., 2021) Carnis, Jerome; Kirner, Felizitas; Lapkin, Dmitry; Sturm, Sebastian; Kim, Young Yong; Baburin, Igor A.; Khubbutdinov, Ruslan; Ignatenko, Alexandr; Iashina, Ekaterina; Mistonov, Alexander; Steegemans, Tristan; Wieck, Thomas; Gemming, Thomas; Lubk, Axel; Lazarev, Sergey; Sprung, Michael; Vartanyants, Ivan A.; Sturm, Elena V.
    Correction for ‘Exploring the 3D structure and defects of a self-assembled gold mesocrystal by coherent X-ray diffraction imaging’ by Jerome Carnis et al., Nanoscale, 2021, DOI: 10.1039/D1NR01806J.
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    Microstructural defects in hot deformed and as-transformed τ-MnAl-C
    (Lausanne : Elsevier, 2021) Zhao, P.; Feng, L.; Nielsch, K.; Woodcock, T.G.
    In this study, detailed microstructural characterisation has been conducted in both as-transformed and hot deformed samples of τ-MnAl-C using transmission electron microscopy. After hot deformation, true twins, dislocations, intrinsic stacking faults and precipitates of Mn3AlC are the main defects in the recrystallised grains. True twins and order twins were distinguished based on differences in their diffraction patterns. A significant fraction of non-recrystallised grains existed, which had microstructures based on combinations of high densities of true twins, dislocations, and deformation bands. The formation of the Mn3AlC precipitates was confirmed and related to the reduction of saturation magnetization and the increase in the Curie temperature of τ-MnAl-C after hot deformation. Antiphase boundaries, which are believed to act as nucleation sites for reverse domains, were not observed in the hot deformed sample.
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    Microstructure Evaluation and Impurities in La Containing Silicon Oxynitrides
    (Basel : MDPI, 2021) Hakeem, Abbas Saeed; Ali, Sharafat; Höche, Thomas; Drmosh, Qasem Ahmed; Khan, Amir Azam; Jonson, Bo
    Oxynitride glasses are not yet commercialised primarily due to the impurities present in the network of these glasses. In this work, we investigated the microstructure and instinctive defects in nitrogen rich La-Si-O-N glasses. Glasses were prepared by heating a powder mixture of pure La metal, Si3N4, and SiO2 in a nitrogen atmosphere at 1650-1800 °C. The microstructure and impurities in the glasses were examined by optical microscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy in conjunction with electron energy-loss spectroscopy. Analyses showed that the glasses contain a small amount of spherical metal silicide particles, mostly amorphous or poorly crystalline, and having sizes typically ranging from 1 µm and less. The amount of silicide was estimated to be less than 2 vol. %. There was no systematic relation between silicide formation and glass composition or preparation temperature. The microstructure examination revealed that the opacity of these nitrogen rich glasses is due to the elemental Si arise from the decomposition reaction of silicon nitride and silicon oxide, at a high temperature above ~1600 °C and from the metallic silicide particles formed by the reduction of silicon oxide and silicon nitride at an early stage of reaction to form a silicide intermetallic with the La metal.