Pd-capped nanocrystalline Mg films were prepared by electron beam evaporation and hydrogenated under isothermal conditions to investigate the hydrogen absorption process via ion beam techniques and in situ optical methods. Films were characterized by different techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA) provided a detailed compositional depth profile of the films during hydrogenation. Gas-solid reaction kinetics theory applied to ERDA data revealed a H absorption mechanism controlled by H diffusion. This rate-limiting step was also confirmed by XRD measurements. The diffusion coefficient (D) was also determined via RBS and ERDA, with a value of (1.1±0.1)·10−13 cm2/s at 140 ∘C. Results confirm the validity of IBA to monitor the hydrogenation process and to extract the control mechanism of the process. The H kinetic information given by optical methods is strongly influenced by the optical absorption of the magnesium layer, revealing that thinner films are needed to extract further and reliable information from that technique.

中文翻译：

---

离子束技术和光学方法追踪 Pd 封端 Mg 薄膜的等温吸氢过程


通过电子束蒸发制备 Pd 封端纳米晶 Mg 薄膜，并在等温条件下加氢，以研究通过离子束技术和原位光学方法的氢吸收过程。通过 X 射线衍射 （XRD） 和扫描电子显微镜 （SEM） 等不同技术对薄膜进行表征。卢瑟福背向散射光谱法 （RBS） 和弹性反冲检测分析 （ERDA） 提供了氢化过程中薄膜的详细成分深度剖面。应用于 ERDA 数据的气固反应动力学理论揭示了由 H 扩散控制的 H 吸收机制。XRD 测量也证实了这一限速步骤。还通过 RBS 和 ERDA 测定扩散系数 （D），在 140 ∘C 时值为 （1.1±0.1）·10−13 cm2/s。结果证实了 IBA 监测加氢过程和提取过程控制机制的有效性。光学方法给出的 H 动力学信息受到镁层光吸收的强烈影响，这表明需要更薄的薄膜才能从该技术中提取进一步可靠的信息。