Samples where these materials are mixed with other conducting or insulating compounds can also result in a mixed conductive/insulating sample. Oxidation of these types of samples (e.g., graphene oxide) or their functionalization (e.g., functionalized CNTs) can result in them behaving less conductively or as a mixed conductive/insulating material. Usually, we mount these on a double-sided adhesive which works well but electrically isolates the sample.

However, many of these types of samples come as a small volume of powders or flakes which are very difficult to mount. While these types of samples are generally conductive and if they can be mounted in a manor (in electrical contact with the sample stage) to take advantage of this one should do so. Note that the well characterized value of 284.5 eV for graphitic carbon is also a strong indicator that this value is not appropriate as a value to use for AdC charge referencing.

An average of values for graphite from 21 references from the NIST database is 284.46 eV with a standard deviation of 0.14 eV. Materials of a graphitic nature (e.g., graphite, graphene, carbon nanotubes etc.) will have a C 1s main peak, attributed to C=C, which can be used as a charge reference set to 284.5 eV.