Depth Profiling of Hydrogen Isotopes in Metals by Elastic Recoil Detection and Nuclear Reaction Techniques under In‐Situ Conditions

Abstract

AbstractThe application of the ERD‐technique with 2.8 MeV and 25 MeV α‐particles respectively and of the specific nuclear reaction D(d,p)T for the determination of hydrogen isotopes in metals is described in detail. — The methods were applied to hydrided and/or deuterated elements (Ti, Zr, Pd), alloys (Pd0.92Y0.08, Fecralloy, steels), intermetallic compounds (TiMn‐ and ZrMn‐Laves phases) and a Ti/Cu‐target containing all the three hydrogen isotopes. — Images are obtained about the hydrogen depth distribution in near surface regions of the materials (roughly 400 nm in case of 2.8 MeV ERD, 200 um in case of 25 MeV ERD, and 500 nm in case of D(d,p)T). By aid of standardization the hydrogen content of a number of samples was determined. Information was obtained about the presence of impurities in the specimens. Prominent results of the investigations are: Laves‐phase systems (Ti0.4Mn0.6, Zr0.33Mn0.67) are activated for hydrogen absorption by segregation processes, whereby overlayers of Ti(Zr)‐hydride are formed. These overlayers are separated from the bulk‐hydride by a hydrogen depletion zone. Cold‐rolled specimens (Pd, Pd0.92Y0.08) trap hydrogen in near surface states. Surface oxidation of Fecralloy leads to an effective barrier for hydrogen‐uptake, due to the formation of Al‐oxide overlayers.