alpha. -hydride (Fe/sub 0. 8/Ni/sub 0. 2/)TiH/sub chi/; The distribution and manifestation of dissolved hydrogen

• Published in: Materials research bulletin 1989-06, Vol.24:6
• Main Authors: Raj, P., Suryanarayana, P., Sathyamoorthy, A., Iyer, R.M.
• Format: Article
• Language: English
• Subjects: 360201 - Ceramics, Cermets, & Refractories- Preparation & Fabrication; 360202 - Ceramics, Cermets, & Refractories- Structure & Phase Studies; 400102 - Chemical & Spectral Procedures; 400201 - Chemical & Physicochemical Properties; ATOMS; CHALCOGENIDES; CHEMICAL PREPARATION; CHEMICAL REACTION KINETICS; DEBYE TEMPERATURE; DISSOLVED GASES; ELEMENTS; FLUIDS; GAMMA SPECTROMETERS; GASES; HYDRIDES; HYDROGEN; HYDROGEN COMPOUNDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; IRON COMPOUNDS; IRON HYDRIDES; KINETICS; MATERIALS SCIENCE; MEASURING INSTRUMENTS; MOESSBAUER SPECTROMETERS; NICKEL COMPOUNDS; NICKEL HYDRIDES; NONMETALS; OXIDES; OXYGEN COMPOUNDS; PHASE STUDIES; REACTION KINETICS; SOLUTES; SPECTROMETERS; SYNTHESIS; TITANIUM COMPOUNDS; TITANIUM HYDRIDES; TRANSITION ELEMENT COMPOUNDS
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/0025-5408(89)90088-3

Cubic {alpha}-hydride (Fe/sub 0.8/Ni/sub 0.2/)TiH/sub chi/ is prepared with rather large dissolved hydrogen, chi=0.14, by cycling a number of times before freezing the sample along the desorption route. From Mossbauer studies, it is inferred that the hydrogen is uniformly distributed in the bulk and manifests itself, most markedly, in appreciably reducing the Debye temperature and the force constant experienced by Fe atoms. Estimate of volume per H- atom further supports the uniform bulk distribution of dissolved hydrogen. Using conversion electron Mossbauer spectroscopy, it is shown that there is no hydrogen rich phase at the surface of {alpha}-hydride. Instead, as a result of cycling, an appreciable amount of a ternary oxide phase is formed at the surface.