Grain rotation in nanocrystalline layers under influence of swift heavy ions
| Autor: | Gerhard Schumacher, Nora Darowski, Jürgen W. Gerlach, Siegfried Klaumünzer, Ivo Zizak, Walter Assmann |
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| Přispěvatelé: | ZIZAK, Ivo |
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Nuclear and High Energy Physics
Materials science Ion beam Condensed matter physics Ion Hammering Disclination Material Modification Nanocrystalline material [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] Amorphous solid Condensed Matter::Materials Science Grain growth Crystallography Nanocrystal Nanocrystalline Materials Grain boundary SHIM Texture Instrumentation Grain boundary strengthening |
| Popis: | Significant changes in texture occur in nanocrystalline Ti, TiN and NiO layers during irradiation with 350 MeV Au ions. The angle between ion beam and layer normal Θ was between 30° and 70°. The major effect is a collective rotation of the nanocrystals. In case of ω layers the texture rotated by more than 70° at an ion fluence Φ t = 3 × 10 15 Au / cm 2 . In addition to grain rotation, the layers exhibit a shear motion like that observed previously with amorphous materials. Below about 1 × 10 15 Au / cm 2 the grain growth is small and grain rotation is reversible, i.e. reversing the sign of Θ and applying the same Φ t , the grains roll back into their original orientation. The second observed effect is the alignment of the grains, whose coalescence eventually leads to a mosaic crystal. However, grain rotation is absent or immeasurably small in micro-crystalline titanium. An attempt to understand the processes in nanocrystalline materials in terms of amorphous grain boundaries, as well as the disclination dipole diffusion along the grain boundary was made. |
| Databáze: | OpenAIRE |
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