Solute trapping of hydrogen in niobium; symmetry of the 0-H pair

Journal Article · Mon Sep 01 04:00:00 EDT 1980 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(80)90083-8· OSTI ID:5105764

Zapp, P E; Birnbaum, H K

Anelastic relaxation techniques in the MHz frequency range were used to study the structure of the O-H pair in niobium and to determine its characteristic relaxation modes. Internal friction peaks were observed for longitudinal stress waves propogating in the <100>, <110> and <111> and two activation enthalpies of motion were measured; 0.18 eV in the <100> and 0.12 eV in the <111>. The apparent binding enthalpies for the two principal relaxations were the same, 0.1 eV. These results are interpreted in terms of the motion of hydrogen around an oxygen interstitial trapping site. The relaxation symmetries are related to the reorientations of nearest neighbor O-H pairs with <100> monoclinic symmetry second nearest neighbor pairs with <100> monoclinic symmetry and third nearest neighbor pairs with <110> monoclinic symmetry. Relations for the relaxation times in terms of atomic jump frequencies along specific reaction paths are developed. The measured parameters are related to the motion of hydrogen along these paths.

• Research Organization: Univ. of Illinois, Urbana-Champaign
• OSTI ID: 5105764
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 28:9; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals &amp; Alloys-- Structure &amp; Phase Studies
360104 -- Metals &amp; Alloys-- Physical Properties
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DIFFUSION
ELEMENTS
ENTHALPY
FRICTION
HYDROGEN
INTERNAL FRICTION
INTERSTITIALS
METALS
NIOBIUM
NONMETALS
PHYSICAL PROPERTIES
POINT DEFECTS
REFRACTORY METALS
RELAXATION
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRAPPING