Abstract
The susceptibility to irradiation-induced damage, the fundamental mechanism of the relaxation kinetics, and the corresponding recrystallization effect related to the cation radius ratio are comprehensively investigated for Y3Al5O12 and Gd3Ga5O12 garnet crystals under 645 MeV Xe35+ irradiation with different fluences of 5 × 1011–3 × 1012 ions cm−2. Regarding different lattice distortion and swelling levels, the observed microstructure transformations to disordered and amorphous phases, and corresponding hillock dimensions, consistently confirm that Gd3Ga5O12 has a higher susceptibility to radiation damage than Y3Al5O12. Combined with iTS model calculations, although Y3Al5O12 has higher atomic temperature and energy deposition than Gd3Ga5O12 under the same ion velocity and electronic energy loss, the relatively high thermal conductivity and specific heat coefficient of Y3Al5O12 crystals enhance the conduction and dissipation of deposition energy, and Gd3Ga5O12, with a higher cation-radius-ratio (rA/rB), is more easily damaged to amorphous phase due to the less favorable kinetics of ordering and recovery of a melted track region to the crystalline phase. Additionally, the significant bandgap modification in spectral ranges of 5.88–6.75 eV for Y3Al5O12 and 4.83–5.41 eV for Gd3Ga5O12, and the enhancement of defect-assisted-related luminescence are achieved, providing a basis to design novel optoelectronic devices in microelectronics fields.
