In situ synchrotron 57Fe Mössbauer spectroscopy of RFe2 (R=Y,Gd) hydrides synthesized under ultra-high-pressure hydrogen

• Published in: Journal of alloys and compounds Vol. 580; pp. S264 - S267
• Main Authors: Mitsui, T., Masuda, R., Seto, M., Hirao, N., Matsuoka, T., Nakamura, Y., Sakaki, K., Enoki, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 01.12.2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; High-pressure; High-pressure and shock-wave effects in solids and liquids; Hydrogen absorbing materials; Hyperfine interactions; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Mechanical and acoustical properties of condensed matter; Metal hydrides; Mössbauer spectroscopy; Phase transitions; Physics; Metal hydrides; Hydrogen absorbing materials; Hyperfine interactions; Phase transitions; High-pressure; Mössbauer spectroscopy; High-pressure effects; Hydrogen storage; Intermetallic compounds; Moessbauer spectroscopy; Isomer shift; Hydrides; Magnetic transitions; High pressure; Quadrupolar splitting; Diamond anvil; Laves phases; Iron additions; Synchrotron radiation
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.03.271

•We report the high pressure Mössbauer studies of C15 Laves RFe2 (R=Y,Gd) hydrides.•Two-step magnetic transition was found in C15 Laves RFe2 under high pressure H2.•Pressure induced magnetic transition of RFe2 hydride was not affected by R atom. In situ synchrotron radiation 57Fe Mössbauer spectroscopy was used to study the C15 Laves phases RFe2 (R=Y,Gd) under ultra-high-pressure hydrogen in a diamond anvil cell. In both cases, the 57Fe isomer shift showed a rapid increase at a few GPa, and once again showed a small increase at above P∼10GPa. The quadrupole splitting also showed stepwise changes. As a marked effect, a two-step magnetic transition was clearly observed for RFe2 (R=Y,Gd). The results indicate that two different hydride phases appear in the RFe2–H reaction system under the hydrogen pressure (up to 34GPa).