Grain rotation in nanocrystalline layers under influence of swift heavy ions

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:267

Article; Proceedings Paper

Zizak, Ivo¹  Darowski, Nora²  Klaumuenzer, Siegfried²  Schumacher, Gerhard²  Gerlach, Juergen W.³  Assmann, Walter⁴ 

[1] Berliner Elektronenspeicherring Gesell Synchrotro, D-12489 Berlin, Germany

[2] Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany

[3] Leibniz Inst Oberflachenmodifizierung, D-04318 Leipzig, Germany

[4] Univ Munich, D-85748 Garching, Germany

关键词: SHIM;    Material modification;    Texture;    Ion hammering;    Nanocrystalline materials;   

DOI  :  10.1016/j.nimb.2009.02.018

来源: Elsevier

【 摘 要 】

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 Theta was between 30 degrees and 70 degrees. The major effect is a collective rotation of the nanocrystals. In case of omega layers the texture rotated by more than 70 degrees at an ion fluence Phi t = 3 X 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 x 10(15) Au/cm(2) the grain growth is small and grain rotation is reversible, i.e. reversing the sign of Theta and applying the same Phi 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. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

Free