Quantitative laser atom probe analyses of hydrogenation-disproportionated Nd–Fe–B powders

We report a successful atom probe tomography of hydrides in hydrogenation-disproportionated Nd–Fe–B powder using a green femtosecond laser. The atom probe specimens were prepared from one particle of powder using the focused ion beam lift-out method. The atom probe tomography taken from an α-Fe/NdH2 structure suggested that B and Ga (trace added element) were partitioned in the NdH2 phase. The hydrogen concentration of 64 at% determined from the atom probe analysis was in excellent agreement with the stoichiometry of the NdH2 phase.

Research Highlights
► Atom probe tomography of hydrides in hydrogenation-disproportionated Nd–Fe–B powder.
► Successful quantitative analysis of hydrogen from NdH2 lamellae.
► Direct observation of individual hydrogen atoms using laser assisted atom probe.