naa a22 4500 551458208 CHVBK 20181215081821.0 cr unu---uuuuu 181215e201810 xx s 000 0 eng 10.1016/j.micron.2018.05.010 doi (SERVAL)BIB_804ABD450075 29945119 pmid 000442979900004 isiid Three-dimensional scanning transmission electron microscopy of dislocation loops in tungsten [Elektronische Daten] [S. Hasanzadeh, R. Schäublin, B. Décamps, V. Rousson, E. Autissier, M.F. Barthe, C. Hébert] Scanning transmission electron microscopy (STEM) imaging using diffraction contrast is a powerful technique to assess crystal defects. In this work it is used to assess the spatial distribution of radiation induced defect in tungsten. In effect, its irradiation leads to the formation of nanometric dislocation loops that under certain conditions may form intriguing 3-D rafts. In this study, we have irradiated thin tungsten samples in situ in a TEM with 1.2 MeV W ions to 0.017 dpa at room temperature (RT) and at 700 °C. Besides the Burgers vector analysis, the number density and size of the dislocation loops with their spatial arrangement were quantitatively characterized by stereo imaging in STEM mode. Most of the loops have a Burgers vector ½ a &lt;sub&gt;0&lt;/sub&gt; 〈111〉, with some a &lt;sub&gt;0&lt;/sub&gt; 〈100〉 at room temperature. Loops are located mainly in the simulated damage profile but there is also a significant portion in deeper regions of the sample, indicating that loops in W diffuse easily, even at RT. At 700 °C, loops form elongated rafts that contain dislocation segments having a Burgers vector ½ a &lt;sub&gt;0&lt;/sub&gt; 〈111〉. The rafts are narrow and reside on {111} planes; they are elongated along 〈110〉 directions, which correspond, when combined to the rafts' Burgers vector, to the lines of edge dislocations. Compared to conventional TEM, 3-D analysis in STEM appears thus as a powerful technique for quantitative analyses of defects in tungsten, as it allows reducing the background diffraction contrast and reaching thicker areas of the electron transparent foil, here 0.5 μm of tungsten at 200 kV. Hasanzadeh S. aut Schäublin R. aut Décamps B. aut Rousson V. aut Autissier E. aut Barthe M.F. aut Hébert C. aut Micron 113(2018-10), 24-33 113<24-33 2018 113 1 article serval SERVAL 700 1- Hasanzadeh S. aut SERVAL 700 1- Schäublin R. aut SERVAL 700 1- Décamps B. aut SERVAL 700 1- Rousson V. aut SERVAL 700 1- Autissier E. aut SERVAL 700 1- Barthe M.F. aut SERVAL 700 1- Hébert C. aut SERVAL 773 0- Micron 113(2018-10), 24-33 113<24-33 2018 113 BK010053 XK010053 XK010000 SERVAL SERVAL SERVAL article