Radiation effects in yttria-stabilized zirconia: Comparison between nuclear and electronic processes

Yttria-stabilized zirconia (YSZ) single crystals were irradiated with heavy ions at energies ranging from a few MeV to a few GeV in order to compare the effects of nuclear collisions and electronic excitations. The amount of damage created by irradiation was measured as a function of the ion fluence by Rutherford backscattering and channeling spectrometry (RBS/C). Monte-Carlo simulations of RBS/C data show that both the depth distributions of radiation damage and the damage build-up strongly depend on the type of irradiation. At low energy (4MeV Au ions) the damage exhibits a peak around the ion projected range (∼500nm) and it accumulates with a double-step process; at high energy (940MeV Pb ions) the damage profiles are rather flat up to several micrometers and the damage accumulation is monotonous (one-step). RBS/C and X-ray diffraction results show that the various irradiations never lead to total disordering of irradiated layers (amorphization), even at the highest fluences used in the experiments.