Ion Beam Irradiation of Nanodiamonds

Nanodiamonds, which are nano-sized diamond crystals, have potential biomedical applications due to their fluorescent properties. In order for the nanodiamonds to fluoresce, however, permanent defects must be added to the crystalline sample. One way in which this can be done is to induce lattice defects with irradiation with an accelerated ion beam. A method has been developed using the Hope College Ion Beam Analysis Lab (HIBAL) to irradiate nanodiamonds. An accelerated beam of protons incident on the nanodiamond samples creates vacancies in the diamond structure. Annealing of these irradiated samples causes the vacancies to migrate towards natural nitrogen impurities in the diamond, making the vacancies permanent. Using cathodoluminescence, the fluorescent properties of irradiated nanodiamonds can be measured. Preliminary data show that irradiated nanodiamonds fluoresce around 625 nm, whereas non-irradiated nanodiamonds fluoresce around 520 nm. Future work will include refinement of a robust method to irradiate larger quantities of nanodiamonds and writing a grant proposal to fund this novel initiative