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Microscopic structural change in a liquid Fe‐C alloy of ~5 GPa
Author(s) -
Shibazaki Yuki,
Kono Yoshio,
Fei Yingwei
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl064271
Subject(s) - alloy , diffraction , structural change , materials science , structure factor , crystallography , x ray crystallography , radial distribution function , condensed matter physics , analytical chemistry (journal) , chemistry , molecular dynamics , metallurgy , optics , physics , computational chemistry , chromatography , economics , macroeconomics
The structure of a liquid Fe‐3.5 wt % C alloy is examined for up to 7.2 GPa via multiangle energy‐dispersive X‐ray diffraction using a Paris‐Edinburgh type large‐volume press. X‐ray diffraction data show clear changes in the pressure‐dependent peak positions of structure factor and reduced pair distribution function at 5 GPa. These results suggest that the liquid Fe‐3.5 wt % C alloys change structurally at approximately 5 GPa. This finding serves as a microscopic explanation for the alloy's previously observed density change at the same pressure. The pressure dependencies of the nearest and second neighbor distances of the liquid Fe‐3.5 wt % C alloy are similar to those of liquid Fe which exhibits a structural change near the bcc‐fcc ‐liquid triple point (5.2 GPa and 1991 K). Similarities between Fe‐3.5 wt % C and Fe suggest that a density change also occurs in liquid Fe and that this structural change extends to other Fe‐light element alloys.