Enhanced surface flatness of vitrinite particles by broad ion beam polishing and implications for reflectance measurements

Using broad ion beam polishing the vitrinite reflectance increases by 0.18-0.24% VRr (relative increase: 12-28%) in coal samples (including an ICCP standard sample) and by 4.76% VRmax (relative increase: 90%) at a measured graphite without causing thermal overprinting of the sample based on our preliminary results. A subsequent traditional polishing step after broad ion beam polishing reverses this increase in reflectivity. The presented method has the potential to decrease the range of reflectance-based calculated maximum burial temperatures by up to 50 °C if a reduction of 0.2 in the range of the measured vitrinite reflectance standard deviation can be achieved.