Regensburg 2004 – wissenschaftliches Programm

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M: Metallphysik

M 24: Nanoskalige Materialien III

M 24.2: Vortrag

Donnerstag, 11. März 2004, 10:30–10:45, H16

Analysis of nanocrystalline CuBi-layers — •Daniel Wolde-Giorgis, Talaát Al-Kassab und Reiner Kirchheim — Universität Göttingen, Institut für Materialphysik, Tammanstraße 1, 37077 Göttingen

The segregation behaviour of Bi in nanocrystalline Cu-layers was investigated by means of the tomographic atom probe (TAP) and field ion microscopy (FIM). The investigated layers were prepared by sputter deposition on W-substrates. These substrates have the shape of tips with a radius of curvature of up to 60nm. Using a Kaufmann Ar-ionsource and a deposition rate of 0.4 Å, we obtain a nanocrystalline CuBi-layer. FIM analyses confirm the nanocrystalline structure of the deposited layers. TAP analyses show an increased concentration of Bi. This value is about two orders of magnitude higher than the solubility of Bi in Cu which amounts up to 100ppm at 577K. A strong segregation at grain boundaries is expected to occur while annealing. These supersaturated CuBi alloys are therefore ideal model systems for the investigation of the microstructural development.