Creation of color centers in MgF₂ single crystals by swift heavy ions: Energy loss and fluence dependence

Ion-solid interaction leads to significant modifications in the surface and bulk of different materials. MgF₂ of a rutile crystalline structure is an important optical material for a large variety of applications. The single crystals were irradiated with energetic heavy ions of various kinetic energies and fluences. After irradiation, we utilized optical spectroscopy to study the ion-induced defects and their evolutions as a function of ion beam parameters. The absorption spectra show the creation of different types of ion-induced defects, namely F-, F₂-, and F₃-centers. The concentrations of the observed color centers as well as their creation efficiency are studied in terms of ion energy loss and fluence. The results are of high importance for understanding the degradation of optical materials in space environments.