Microscopic Behaviour of Hydrogen and hHydrides in Atom Probe Tomography of Zirconium

The understanding of Zirconium (Zr) and Hydrogen (H) interactions is a topic of interest in the field of materials science. Zr is known to have a strong affinity with hydrogen, which can lead to the formation of hydrides that can affect the mechanical properties (embrittlement, cracking, etc) of the material [1]. Our studies are carried out on pure Zr analysed by laser-assisted atom probe tomography. This is complex, because the hydrogen detected during the analysis could come from the analysis chamber (parasitic hydrogen) or from the material (hydrogen contained in the material). Our results show the formation of hydrogen species H⁺, H₂⁺, H₃⁺ and hydrides ZrH_x²⁺. The evolution of the relative abundances of H⁺, H₂⁺, H₃⁺ depends on the surface field estimated from the Zr³⁺/Zr²⁺ ratios, as seen in previous studies on other materials[2]. This is not the case for the hydrides which overlap with the Zr isotopic species. In this contribution we will discuss the quantification of hydrogen and zirconium hydrides and their dependence on the field.<br/><br/><br/>[1] J. Bair, M. Asle Zaeem, et M. Tonks, « A review on hydride precipitation in zirconium alloys », <i>J. Nucl. Mater.</i>, vol. 466, p. 12, nov. 2015, doi: 10.1016/j.jnucmat.2015.07.014.<br/>[2] L. Rigutti <i>et al.</i>, « Surface Microscopy of Atomic and Molecular Hydrogen from Field-Evaporating Semiconductors », <i>J. Phys. Chem. C</i>, vol. 125, n^o 31, p. 17078, août 2021, doi: 10.1021/acs.jpcc.1c04778.