Abstract : Yttria-stabilized zirconia (YSZ) single crystals were irradiated with 4-MeV Au ions at several temperatures from RT up to 800 degrees C. For each temperature, the amount of damage created by irradiation was measured as a function of the ion fluence by Rutherford backscattering spectrometry in channeling geometry (RBS/C). In all cases the damage exhibits a peak around the ion projected range (similar to 500 nm) and it accumulates via a multi-step process. Furthermore, the damage build-up strongly depends on the irradiation temperature: the occurrence of the second stage of damage accumulation, which presents a high increase of the damage fraction, is shifted towards lower fluences as the temperature is increased. This effect may be explained by enhanced defect-clustering at high temperature. (C) 2011 Elsevier B.V. All rights reserved.