Amorphizable ceramics (LiNbO₃, ZrSiO₄, and Gd₃Ga₅O₁₂) were irradiated with 200 MeV Au ions at an oblique incidence angle, and the as-irradiated samples were observed by transmission electron microscopy (TEM). Ion tracks in amorphizable ceramics are confirmed to be homogenous along the ion paths. Magnified TEM images show the formation of bell-shaped hillocks. The ion track diameter and hillock diameter are similar for all the amorphizable ceramics, while there is a tendency for the hillocks to be slightly bigger than the ion tracks. For SrTiO₃ (STO) and 0.5 wt% niobium-doped STO (Nb-STO), whose hillock formation has not been fully explored, 200 MeV Au ion irradiation and TEM observation were also performed. The ion track diameters in these materials are found to be markedly smaller than the hillock diameters. The ion tracks in these materials exhibit inhomogeneity, which is similar to that reported for non-amorphizable ceramics. On the other hand, the hillocks appear to be amorphous, and the amorphous feature is in contrast to the crystalline feature of hillocks observed in non-amorphizable ceramics. No marked difference is recognized between the nanostructures in STO and those in Nb-STO. The material dependence of the nanostructure formation is explained in terms of the intricate recrystallization process.

The magnetic Compton profiles of Fe–50 at. % Rh intermetallic compound were measured to study the ferromagnetism induced by 200 MeV Xe ion irradiation. The magnetic effect at 50 K increases with increasing the ion-fluence. The analysis of the experimental result revealed that the values of spin moment induced by the irradiation were close to the values of magnetization obtained by a superconducting quantum interference device magnetometer, suggesting that the ion irradiation mainly induces the spin magnetic moment. The difference in magnetic Compton profiles between the irradiation-induced ferromagnetism and the intrinsic ferromagnetism in pure Fe is also discussed.

The size of ion tracks and hillocks produced during heavy ion irradiation of Y₃Fe₅O₁₂ is analyzed by transmission electron microscopy. The cross sections of hillocks and ion tracks produced by ions with electronic stopping power S_e in the range of 20–35 keV/nm are found to be comparable. In this range, the characteristic dimensions of the hillocks (both cross section and height) increase as a function of S_e. The data show that there is a correlation between hillock height and hillock cross section, which is linked to the relation between lifetime of the melt along the ion trajectory and the maximum molten area. In addition, the results clearly show that the size of the hillocks produced by low velocity ions is larger than those produced by high velocity ions of the same S_e, due to the so-called velocity effect.

The microstructure of virgin and heavy ion-irradiated Ce_1–xGd_xO_2–x/2 with a wide range of Gd dopant concentrations (0 ≤ x_Gd ≤ 0.5) was evaluated by x-ray diffraction (XRD), micro-Raman spectroscopy, and transmission electron microscopy (TEM) for selected area electron diffraction (SAED) analysis and plane-view bright-field (BF) imaging of ion tracks. The Ce_1–xGd_xO_2–x/2 samples were irradiated with 200-MeV Xe¹⁴⁺ ions up to fluences from 3 × 10¹¹ to 1 × 10¹³ cm⁻² at ambient temperature. XRD patterns of the virgin Ce_1–xGd_xO_2–x/2 samples showed saturation of lattice parameter and relaxation of microstrain in Ce_1–xGd_xO_2–x/2 which are attributed to the increasing Gd concentration. Moreover, micro-Raman spectroscopy and SAED patterns revealed the bixbyite (C-type) structure formation and oxygen vacancy ordering for x_Gd > 0.2 that is induced by dispersed C-type domains in the fluorite-structured (F-type) matrix. In the irradiated samples, asymmetric XRD peaks induced by lattice distortion were observed together with ion tracks in BF-TEM images. The radiation damage was recovered with the increase of Gd concentration. There is a rapid reduction of radiation damage cross section for x_Gd > 0.2 with a reduction of the C-type structure reflections in XRD and SAED patterns.