Light He and heavy Kr ions irradiation effects in orthorhombic Tb2TiO5 ceramics

Abstract Polycrystalline Tb 2 TiO 5 pellets with orthorhombic structure were irradiated with 400 keV He + and 800 keV Kr 2+ ions at room temperature. Ion-irradiation-induced microstructural evolution is characterized using grazing incidence X-ray diffraction and cross-section transmission electron microscopy. A crystalline to amorphous transformation was observed in orthorhombic Tb 2 TiO 5 as the samples were irradiated with heavy Kr 2+ ions. However, the orthorhombic Tb 2 TiO 5 was observed to transform into a cubic fluorite structure for light He + irradiation. Furthermore, this phase transformation is accompanied by a decrease in unit cell volume of approximately 4.53%. No amorphization was observed even to the highest fluence of 2 × 10 17  He/cm 2 . The observations are discussed on the basis of dense cascade and defects accumulation from heavy and light ion irradiation, respectively. Moreover, the electronic to nuclear stopping power is introduced to help better understand the He and Kr irradiation results.