Radiation stability of nanostructured hydroxyapatite with different interfacial structure is studied. Hydroxyapatite nanoparticle (HAp-np) is fabricated by calcination in muffle furnace and densified nanocrystalline hydroxyapatite (HAp-nc) is synthesized by spark plasma sintering. X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterizations show the hexagonal structure for both HAp-np and HAp-nc. Irradiation responses of HAp-np and HAp-nc are studied via in situ TEM techniques. The samples are irradiated with 1 MeV Kr²⁺ ions over the temperature range of 150 K to 523 K. In situ TEM observations reveal a higher critical amorphization dose of HAp-nc (0.075 dpa) compared to 0.05 dpa of HAp-np at room temperature, indicating enhanced amorphization resistance. The radiation tolerance shows a great dependence on temperature, and a higher critical dose can be observed at elevated temperatures. A lower critical amorphization temperature (T_c) of HAp-nc (∼437 K) than HAp-np (∼545 K) indicates better radiation tolerance since the lower T_c shows better defect annealing ability. This better radiation tolerance of HAp-nc is attributed to the higher sink strength and lower interface energy carried by densified grain boundaries as free-standing open surfaces of HAp-np can carry more isolated dangling bonds that results in a higher interface energy. This excess interface energy can lower the energy difference between crystalline phase and amorphous state, leading to HAp-np to be less radiation resistant. Radiation-induced amorphization is attributed to the accumulation of oxygen vacancies and the glass-like structure rearranged by displaced oxygen and phosphorus atoms.

研究了具有不同界面结构的纳米结构羟基磷灰石的辐射稳定性。通过在马弗炉中煅烧制备羟基磷灰石纳米颗粒 (HAp-np)，通过放电等离子烧结合成致密纳米晶羟基磷灰石 (HAp-nc)。X 射线衍射 (XRD) 和透射电子显微镜 (TEM) 表征显示了 HAp-np 和 HAp-nc 的六边形结构。通过原位TEM 技术研究了 HAp-np 和 HAp-nc 的辐照响应。在150 K 至 523 K 的温度范围内用 1 MeV Kr ²⁺离子辐照样品。原位TEM 观察显示，与室温下 HAp-np 的 0.05 dpa 相比，HAp-nc (0.075 dpa) 的临界非晶化剂量更高，表明非晶化抗性增强。辐射耐受性对温度有很大的依赖性，在升高的温度下可以观察到更高的临界剂量。较低的临界温度非晶（Ť _ç HAP-NC（~437 K）比的HAp-NP（~545 K）的）表示由于下更好耐辐射Ť _Ç显示出更好的缺陷退火能力。HAp-nc 的这种更好的辐射耐受性归因于致密的晶界具有更高的汇强度和更低的界面能，因为 HAp-np 的独立开放表面可以携带更多孤立的悬空键，从而导致更高的界面能。这种过量的界面能可以降低晶相和非晶态之间的能量差，导致 HAp-np 的抗辐射性较差。辐射诱导的非晶化归因于氧空位的积累和由置换的氧和磷原子重新排列的玻璃状结构。