Polishing artifacts

Artifacts introduced through sample preparation are common materials these may be bits of facial tissue, wax, epithelial cells, hair, or dried stain, all inadvertently introduced by the microscopist. Detergent residues on so-called precleaned microscope slides and broken glass are common artifacts, as are knife marks and chatter marks from sectioning with a faulty blade, or scratch marks from grinding and polishing. 

Another problem with all the dwell time methods is that sinee a speeifie diameter tool is often used to do the polishing, the finished surfaee has a "roughness" of a spatial frequency associated with the tool diameter. This rather eo-herent roughness ean produce diffraction artifacts in the image produeed by the telescope. A partial solution to this problem is to use several tool sizes and do the figuring in stages rather than all at onee. 

One problem with the crushing of clinker prior to examination is that microcracks seen in polished-section or thin section study are ambiguously interpreted. Microcracks that are not artifacts of sample preparation may, in some investigations, be related to strain caused by thermal stress (Hornain and Regourd, 1980), crystal reorganization, hydration, and expansion. 

The importance of a well-prepared surface should not be underestimated. The author strongly believes that efforts to produce a high-quality polished section or thin section are rewarded by the relative lack of artifacts which can possibly lead the investigator to incorrect interpretations. Phase identifications free of doubt are worth the extra few minutes of preparation time. 

Accurate porosity data can be obtained by means of quantitative image analysis and microscopy, including electronic methods. However, this requires optimum conditions in the preparation of the polished section, in order to prevent or at least minimize common artifacts, such as ... 

Once the sample has been polished to 3 pm, a final step (fine polishing) usually involving either an alumina slurry or colloidal silica slurry is used. The size of particles in these aqueous slurries can be as small as 0.02 pm. Once finished with this step, the sample is ready for etching. If elemental analysis of the polished sample is to be performed using SEM/EDS or other X-ray techniques, extra care should be taken. Often times artifact silicon or aluminum peaks can be introduced by accumulation of polishing abrasives in cracks and pores, and sometimes, depending on the metal hardness, by intrusion into the sample surface. 

Polish/etch SEM/STEM Oxide/primer 50,000 Polishing artifacts possible preferential attack by etch... 

Polish/etch SEM/STEM Primer/adhesive 50,000 Generally good with restriction of polishing artifacts... 

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