Glassy carbon has properties making it attractive as a containment material for radioactive waste. In this study, the diffusivity of the radiological important fission product, strontium, is measured. Two hundred kiloelectronvolt strontium ions were implanted at room temperature. The implanted samples were either annealed isochronally for 1 h up to 900°C or by increasing the temperature linearly up to 648°C. The Sr profiles were determined by Rutherford backscattering spectrometry (RBS). The isochronally annealed samples showed Fickian diffusion at 300°C (D = 6.7 × 10⁻¹⁹ m² s⁻¹) with segregation occurring at the higher temperatures. Raman spectroscopy indicated a link between damage annealing and the onset of segregation. During increasing temperature, the system is dynamic with diffusion taking place. An equation to determine diffusion coefficients for ramped heating was derived. Fickian diffusion occurred with an activation energy of 1.97 eV for 414–454°C, and from 458 to 558°C, it was 0.184 eV. At higher temperatures, a segregation of the strontium towards the surface was observed. A calculation of the heat of segregation of Sr in carbon supports this segregation. The results show that the in situ RBS measurements with a linear increase in temperature give additional information compared with the conventional isochronal annealing.

玻璃碳具有使其作为放射性废物的密封材料具有吸引力的特性。在这项研究中，测量了放射性重要裂变产物锶的扩散率。在室温下注入了 200 千电子伏的锶离子。植入的样品要么在 900°C 下等时退火 1 小时，要么通过将温度线性升高至 648°C。Sr 分布由卢瑟福背散射光谱法 (RBS) 确定。等时退火样品在 300°C 显示出 Fickian 扩散（D  = 6.7 × 10 ^-19  m ²  s ^-1) 在较高温度下发生偏析。拉曼光谱表明损伤退火和分离开始之间存在联系。在温度升高期间，系统是动态的，发生扩散。推导出确定用于斜坡加热的扩散系数的方程。Fickian 扩散发生时，414-454°C 的活化能为 1.97 eV，458-558°C 为 0.184 eV。在较高温度下，观察到锶向表面偏析。Sr 在碳中的偏析热的计算支持这种偏析。结果表明，与传统的等时退火相比，温度线性增加的原位RBS 测量提供了额外的信息。