Solid breeder materials for fusion power plants are subjected to extreme conditions of radiation damage, high temperature and designed component burn-up. The loss of lattice stability of Li₂TiO₃ due to Li burn-up was investigated using first principles-based approaches to aid evaluation of upper limit of component lifetime. The lattice stability is analyzed using calculated phonon dispersion in the Li₂TiO₃ supercell, while Li burn-up is modeled by the introduction of Li-vacancies. It has been determined that the studied ceramic can be structurally stable up to ∼40% of Li atoms burn-up. At 50% burn-up, the negative frequency branch in the phonon dispersion spectrum appears indicating the loss of lattice dynamical stability. Moreover, the structure obtained by introduction of unstable frozen phonons with minima energy amplitude also results in a phonon dispersion with negative branches in the structure obtained. Therefore, the system completely loses stability when approximately half of Li atoms are consumed.

用于聚变发电厂的固体增殖材料会受到辐射损伤、高温和设计部件烧毁的极端条件的影响。使用基于第一原理的方法研究了由于Li燃耗而导致的Li ₂ TiO ₃晶格稳定性的损失，以帮助评估组件寿命的上限。使用计算的 Li ₂ TiO _{3超级电池}中的声子色散来分析晶格稳定性，同时通过引入锂空位来模拟锂燃耗。已确定所研究的陶瓷在 Li 原子燃耗高达 40% 的情况下结构稳定。在 50% 燃耗时，声子色散谱中出现负频率分支，表明晶格动态稳定性丧失。此外，通过引入具有最小能量幅度的不稳定冻结声子而获得的结构也导致所获得的结构中具有负分支的声子色散。因此，当大约一半的锂原子被消耗时，系统完全失去稳定性。