[en] Y₃Fe₅O₁₂ garnets have been irradiated by Mo and Xe ion beams at 2.3 and 3.3 GeV respectively. High-resolution electron microscopy (HREM), channelling Rutherford backscattering (RBS) and Moessbauer spectrometry have been used to determine the variation of the radius of latent damage tracks induced along the ion paths as a function of the electronic stopping powers between 34 and 56 MeV cm²mg^-1. On comparing the results obtained by different experimental methods it is found that the disorder characterized by channelling RBS measurements extends over the same cylindrical volume as the paramagnetic state observed by Moessbauer spectrometry. A direct HREM measurement of the radii shows a larger cylindrical volume than both the other measurements, indicating the existence of a distorted shell around the disordered core. (author)