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MM: Fachverband Metall- und Materialphysik

MM 20: Poster session

MM 20.26: Poster

Dienstag, 27. März 2007, 14:45–18:00, Poster C

Sample preparation from mechanically alloyed CuFe powders by means of focussed ion beam — •Malte Schmidt, Talaat Al-Kassab, Catharina Wille, and Reiner Kirchheim — Georg-August-Universität Göttingen, Institut für Materialphysik, Friedrich-Hund-Platz 1, D-37077 Göttingen

The focussed ion beam (FIB) has been utilised to shape tip samples for field ion micrsocopy (FIM) and tomographic atom probe (TAP). These tips were prepared from powder particles of Cu_97.5Fe_2.5, Cu₉₅Fe₅ and Cu₉₀Fe₁₀. Such powder particles are first produced using a high-energy planetary ball mill under protective Ar atmosphere, using elemental powders of high purity and milling tools made of hardened steel. Subsequently the milled powder was dusted onto a double-stick carbon tape adhered to a FIB-specimen holder.

A modified lift-out method, which is usually used to fabricate transmission electron microscope lamellae, is applied as a first step of the procedure. After cutting out the lamella of a single particle of the powder, a longish cuboid with an approximate 2µm x 2µm base area is lifted out of the particle and immediately welded onto a modified tungsten tip by means of platinum ion assisted deposition. Subsequently the actual FIM - tip can be shaped out of this cuboid. In this contribution the different steps of the novel procedure are explained and discussed in detail emphasising the sharpening techniques. In addition first results of measurements of such prepared samples will be presented.

Financial support from the Deutsche Forschungsgesellschaft under contract KI-230/33-1 is gratefully acknowledged.