ULTRAFAST LASERS - A PATHWAY TO UNDERSTANDING THE DYNAMIC BEHAVIOR OF SWIFT HEAVY ION IRRADIATION

Swift heavy ions (SHIs) are used in a variety of technological processes to manipulate the nanoscale properties of materials and to simulate fission track formation and annealing. SHIs cause damage by inducing intense electronic excitations along trajectories microns long and only a few nm wide. An unfortunate consequence of this small radius is that time-resolved experiments are impossible, meaning that a complete understanding of SHI-material interaction is out of reach. In this work, we show that ultrafast lasers, which cause an identical damage process compared to SHIs, show potential in bridging this gap due to the ease of performing time-resolved pump-probe experiments. Cubic-to-monoclinic and monoclinic-to-tetragonal phase transformations were induced in Gd₂O₃ and ZrO₂, respectively, by ultrafast laser irradiation. Results were confirmed by Raman spectroscopy and grazing incidence X-ray diffraction. The new phases formed by ultrafast laser irradiation are high temperature polymorphs of the two materials, and these phases are identical to those produced by irradiation with SHIs. Overall, this proof-of-concept experiment shows a promising link between ultrafast laser and SHI irradiation.