Glow discharge plasma as a surface preparation tool for microstructure investigations

In order to reveal the true microstructure of a sample one must often go through tedious and time-consuming surface preparation steps. The most abundant ones are polishing and etching using hazardous chemicals. Sputtering in the glow discharge (GD) lends itself as a simple preparation tool, which supplies mild but fast removal of the deformation layer and exposure of the microstructure. However, the GD is not well studied in terms of its use for preparation of samples. In the present work the influence of GD sputtering on the sample surface is systematically studied. Some examples of the samples prepared with GD are shown. Polycrystalline Cu needs up to 8 h to be conventionally prepared, while with GD the same surface is reached after 10 s of sputtering. In the case of the Ti40Nb alloy, sputtering in GD is the best method for the preparation of this material only within 5 min. The successful EBSD-measurements of the considered samples approve the good quality of the prepared surfaces. Various artifacts of sputtering are found. On the one hand they disturb the measurement, but on the other hand, they may contain useful information about the sputtered material.