Atoms and Nanoparticles of Transition Metals as Catalysts for Hydrogen Desorption from Magnesium Hydride

Table 2

Results of the Nb K-edge EXAFS analysis on Nb-doped Mg films; for each pair of atoms, N is the coordination number, R the interatomic distance, and 𝜎² the Debye-Waller factor. The uncertainty in the fitting results corresponds to a confidence level of 68%. Crystallographic data for metallic Nb and the simulation of the local structure around an Nb substitutional impurity into the Mg lattice are also reported.

Sample		N	R (Å)	𝜎^2 (10^−4Å^2)
As-deposited	Nb-Nb	1.2 ± 0.4	2.73 ± 0.01	38 ± 9
	Nb-Mg	9.6 ± 0.9	3.08 ± 0.01	99 ± 8
Hydrogenated	Nb-Nb	5.6 ± 0.3	3.00 ± 0.02	57 ± 6
	Nb-Nb	4.2 ± 0.2	3.45 ± 0.02	66 ± 8
dehydrogenated	Nb-Nb	4.0 ± 0.2	2.87 ± 0.01	44 ± 4
	Nb-Nb	3.0 ± 0.2	3.32 ± 0.01	40 ± 4
metallic Nb	Nb-Nb	8	2.8638
	Nb-Nb	6	3.3068
Nb-doped Mg (simulation)	Nb-Mg	6	3.075
	Nb-Mg	6	3.195