Very Sharp Platinum Tips by Electrochemical Etching

4 Tip properties Martin Kupper 0830965Figure 4.2: Grain boundaries after the micropolishing. The upper right picture wastaken with the back scattering detector, the others with 5kV accelerationvoltage. On the lower pictures the same tip is shown; the picture on theright shows that there is a grain boundary at the point the micro-wirebegins.SEM was insufficient. In the right, lower picture a grain boundary can be seen at thepoint where the micro-wire begins. We expected to see smaller grains on micropolishedunannealed tips, but we did not (Fig.4.3).16