Kr irradiation effects and annealing behaviour of a monosilicated Nd-substituted fluorapatite studied by X-ray diffraction

A monosilicated sintered fluorapatite (Ca9Nd(PO4)5(SiO4)F2, britholite) was irradiated in the electronic stopping power regime with 85.8 MeV Krypton ions. The induced damage was characterized by means of X-ray diffraction. Following the evolution of crystallographic lattice parameters and the characteristic changes in the X-ray diffraction spectra, we showed the progressive damaging of this material. By calculating an effective radius (Re), damage in this britholite was quantified. The behaviour under thermal annealing was also studied by X-ray diffraction, using different durations of isothermal annealing (300 °C) in order to follow the structural rebuilding of the crystallographic lattice. From the evolution of the peak areas, we concluded that there is a partial rebuilding of the structure. This variation may be divided in two steps, according to the lattice parameters changes.