SANS measurements of deuterium trapped at grain boundaries in palladium

Brent Heuser, John S. King, George C. Summerfield

Research output: Contribution to journalConference article

Abstract

Small-angle neutron scattering from grain boundary interfaces has been investigated in polycrystal palladium with and without deuterium dissolved in the solution phase. Polycrystalline samples were prepared using two different procedures: (1) single crystal material was recrystallized at 517°C after 78% cold working, and (2) an extruded polycrystal rod was investigated as received, or recrystallized at 600°C. The expected 1/Q2 scattering profile (where Q is the neutron wavevector transfer) from grain boundaries has been observed and the absolute cross sections permit a determination of the grain boundary surface concentration of missing palladium atoms and of trapped deuterium. The vacancy and trapped deuterium surface concentration of missing palladium atoms and of trapped deuterium. The vacancy and trapped deuterium surface concentration determined in these measurements was 0.2-3 vacancies/ A2 and 0.4-0.6 deuterons/A2, respectively. The measurements were extended to the low Q region (Q ≥ 0.006 1/A) where the scattering response was dominated by Porod 1/Q4 behavior typical of internal voids. This behavior was especially strong for the samples fabricated from the extruded polycrystal, but was also present in the as-received single crystal. The degradation of the single crystal Porod response after compressional cold working is in reasonable agreement with the calculated effect of flattening a spherical void.

Original languageEnglish (US)
Pages (from-to)339-344
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
Volume319
StatePublished - Jan 1 1994
Externally publishedYes
EventProceedings of the MRS 1993 Fall Meeting - Boston, MA, USA
Duration: Nov 29 1993Dec 2 1993

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ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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