Raman spectroscopy study of damage in swift heavy ion-irradiated ceramics

International audienceRaman scattering is applied to probe the radiation damage in swift heavy ion-irradiated ceramics, namely zirconium nitride (ZrN), ceria (CeO$_2$), and yttria-stabilized zirconia (ZrO$_2$: Y, or YSZ) for about the same high electronic stopping powers of heavy ions. Raman spectra show that those ceramics are radiation-resistant materials which are not amorphized by such irradiations even for large track overlap at high fluences. However, the increase of the TA/LA and TO/LO band intensities versus fluence is evidenced after 100-MeV Xe ion irradiation of ZrN up to a saturation for the fluence of 3x10$^{12}$ cm$^{-2}$. The band growths are ascribed to the increase of the concentration of Zr and N vacancies induced by electronic excitations inside tracks. For ceria, the decrease and broadening of the main F$_{2g}$ peak of the fluorite-like structure and the growth of a broad defect band is observed versus fluence up to 10$^{14}$ cm$^{-2}$ for 200-MeV Xe ion irradiation. For YSZ, Raman spectra mainly give evidence of the intrinsic lattice disorder arising from the native oxygen vacancies, even up to high fluences (3x10$^{13}$ cm$^{-2}$) for 200-MeV I and 200-MeV Au ion irradiation. Results are discussed on the basis of the interplay between the native structural disorder and the radiation-induced disorder by electronic excitation in those three materials