Deuterium (D₂(g)) storage of Pd-coated Ti ultra-thin films at relatively low pressures is fine-tuned by systematically controlling the thicknesses of the catalytic Pd overlayer, underlying Ti ultra-thin film domain, D₂(g) pressure (P_D2), duration of D₂(g) exposure, and the thin film temperature. Structural properties of the Ti/Pd nanofilms are investigated via XRD, XPS, AFM, SEM, and TPD to explore new structure-functionality relationships. Ti/Pd thin film systems are deuterated to obtain a D/Ti ratio of up to 1.53 forming crystallographically ordered titanium deuteride (TiD_x) phases with strong Ti^x+–D^y– electronic interactions and high thermal stability, where >90% of the stored D resides in the Ti component, thermally desorbing at >460 °C in the form of D₂(g). Electronic interaction between Pd and D is weak, yielding metallic (Pd⁰) states where D storage occurs mostly on the Pd film surface (i.e., without forming ordered bulk PdD_x phases) leading to the thermal desorption of primarily DOH(g) and D₂O(g) at <265 °C. D-storage typically increases with increasing Ti film thickness, P_D2, T, and t, whereas D-storage is found to be sensitive to the thickness and the surface roughness of the catalytic Pd overlayer. Optimum Pd film thickness is determined to be 10 nm providing sufficient surface coverage for adequate wetting of the underlying Ti film while offering an appropriate number of surface defects (roughness) for D immobilization and a relatively short transport pathlength for efficient D diffusion from Pd to Ti. The currently used D-storage optimization strategy is also extended to a realistic tritium-based betavoltaic battery (BVB) device producing promising β-particle emission yields of 164 mCi/cm², an open circuit potential (V_OC) of 2.04 V, and a short circuit current (I_SC) of 7.2 nA.

中文翻译：

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钯涂钛纳米膜上的低压氘存储：用于氚基贝塔伏特电池应用的多功能模型系统

通过系统地控制催化 Pd 覆盖层、下面的 Ti 超薄膜域D ₂ (g) 的厚度，可以在相对较低的压力下对 Pd 涂覆的 Ti 超薄膜的氘 (D 2 (g)) 存储_进行微调压力( P _D2 )、D ₂ (g)暴露的持续时间以及薄膜温度。通过 XRD、XPS、AFM、SEM 和 TPD 研究 Ti/Pd 纳米膜的结构特性，以探索新的结构-功能关系。Ti/Pd 薄膜系统经过氘化，可获得高达 1.53 的 D/Ti 比，形成晶体有序的氘化钛 (TiD _x ) 相，具有强 Ti ^{x +} –D ^{y –}电子相互作用和高热稳定性，其中 >90%储存的 D 存在于 Ti 组分中，在 >460 °C 时以 D ₂ (g)的形式热解吸。Pd 和 D 之间的电子相互作用很弱，产生金属 (Pd ⁰ ) 态，其中 D 存储主要发生在 Pd 薄膜表面上（即，没有形成有序的块状 PdD _x相），导致主要是 DOH(g) 和 D 的热解吸<265 °C 时为₂ O(g)。D-存储通常随着Ti膜厚度、 P _D2、T和t的增加而增加，而D-存储被发现对催化Pd覆盖层的厚度和表面粗糙度敏感。最佳 Pd 薄膜厚度确定为 10 nm，提供足够的表面覆盖，以充分润湿下面的 Ti 薄膜，同时为 D 固定提供适当数量的表面缺陷（粗糙度），并为 D 从 Pd 到 Ti 的有效扩散提供相对较短的传输路径长度。_{当前使用的 D 存储优化策略还扩展到现实的氚}基贝塔伏特电池 (BVB) 装置，可产生164 mCi/cm ^{2的有希望的 β}粒子发射产量、2.04 V 的开路电势 ( VOC ) 和短路电流 ( I _SC ) 为 7.2 nA。