Hydrogen sorption in crystalline and amorphous Mg–Cu thin films

Mg-Based Thin Films as Model Systems in the Search for Optimal Hydrogen Storage Materials

“…Mg was also alloyed with Cu to get an improved hydrogen storage properties. It was demonstrated that Pd-capped Mg90Cu10 amorphous thin film can reversibly store 5.8 wt% hydrogen in near ambient condition and could desorb it at temperature around 100 °C [89]. A comprehensive study of several metastable, crystalline single-phase Mg80X20 (X = Sc, Ti, V, Cr) thin film alloys was presented by Niessen and Notten [90].…”

Thickness effects in hydrogen sorption of Mg/Pd thin films

“…For instance, for films of approximately 200 nm in thickness, Higuchi et al [9], in their early work in the field, reported dehydrogenation temperature of 463 K whereas the value reported by Kumar et al [10] was not too far off the ambient conditions (373 K). Similarly, Akyıldız et al [11] reports a Mg based alloy of 300 nm in thickness storing 5 wt.% hydrogen with a desorption temperature of 323 K.…”

Effects of Amorphous and Nanocrystalline Structures on Hydrogen-Induced Optical Performance of Modulated Mg–Gd Films with Various Composition Fluctuations

“…10 Besides, reduction in the crystallization rate of Mg alloy films could improve the hydrogen storage capacities. 2 Moreover, Mg, Mg−Ni, and Mg−Cu amorphous films were deposited 12 by the sputtering method, which was found to be the best choice to deposit amorphous materials with supercooling rate.…”

“…On the one hand, after the annealing process, crystallization including nucleation and grain growth takes place in the amorphous film. 13 The films with Mg/Ni = 10:1 to 3.5:1 were X-ray amorphous when fabricated and then transformed to a crystalline structure after being annealed at 398 K. 12 It was reported that the Pd/Mg film exhibited improvement in its hydrogenation properties after the Mg layer was in situ annealed at 473 K for 2 h. 14 Besides, it was estimated that the Pd/Mg film could completely absorb hydrogen after treatment at 573 K. 15 However, structure evolution inside the Mg films during the annealing process has not been elucidated yet so that the scale of the nanostructured region is hard to control. On the other hand, the annealing process results in numerous side effects, including the formation of Pd−Mg intermetallic compounds between the Pd and Mg layer and the diffusion across the Mg/substrate interface.…”

“…18 Matsuda et al reported that Mg crystallization occurred in films with an initial Mg/Ni ratio of greater than 7.7, which was the eutectic composition between Mg and Mg 2 Ni. 19 12 However, these studies reported the change in the integral composition of the films, for which it was hard to form nanocrystals. Films with the same content ratio but different crystallinity can be fabricated by enlarging their composition fluctuation inside.…”