Analysis of the electrical characteristics and modifications in the crystalline structure of graphite under UV...

Raman intensity ratio ID/IG was analyzed for 2B and 9B graphite-rich pencil rods of 2.6 mm thickness were irradiated by (a) Ultraviolet (UV) sources of 1.12 mW and 2.7 mW; (b) photons doses from 1 to 20 Gy delivered by an Elekta Linac. Additionally, an electrical characterization was carried out using the UV source to analyze the electrical properties of the materials. Graphite exhibits an oscillatory behavior due to the creation and annihilation of defects, thanks to sp2 and sp3 hybridizations in the hexagonal structure. This behavior is observed with both ionizing and non-ionizing sources. Proving that this phenomenon does not depends on the thickness of the material. For the 2B irradiated with UV of 1.12 mW, an underdamped response is observed, for which a mathematical model is presented. Nevertheless, 9B samples exhibit a "fading" response, maintaining the behavior for up to two weeks after the irradiation. In the electrical characterization, this phenomenon has been analyzed before, but the model was compared to a discharge of a capacitor is presented. The results confirmed the behavior of the material mentioned in other articles, but it also shows that the Raman intensity decreases with time, as well as the material's capacity to discharge as a capacitor.