158 Prakt. Met. Sonderband 38 (2006) 
Fig. 3: 3D FIB preparation of rapidly solidified ribbon; a) SE image after partial coarse 
milling; b) Curtains on the area of interest Fig 
The 3D FIB preparation has been performed in three steps. At the beginning a 2 pm thick 
protective Pt layer was deposited on the free surface of the ribbon with the aim to reach a Clos 
sharp edge and a straight indentation. In the second step we performed a coarse and fine that 
milling. The initial cut was done roughly at high energy levels (1 nA) to remove the bulk of resc 
the material (Fig. 3a). Following the coarse mill a fine mill with the same width and pattern of tt 
was performed. The beam current for this mill was much lower (about 0.25 nA) and a longer thar 
scan time was used to obtain clean and contrast-rich cross sections. However, vertical ribs, calle 
the so called curtains, which are artifacts of FIB preparation, appeared on the area of fron 
interest (Fig. 3b). Therefore, additional cleaning and FIB-etching with an ion current of 10 pA Unf 
was used to reveal the structure. This resulted in a high-contrast microstructure with well sec 
developed grains (Fig. 4a). solir