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Diffusion in the intermetallic phase Fe 3 Si under hydrostatic pressure
Author(s) -
Gude A.,
Freitag K.,
Sepiol B.,
Vogl G.,
Mehrer H.
Publication year - 1996
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221970204
Subject(s) - intermetallic , diffusion , hydrostatic pressure , materials science , vacancy defect , volume (thermodynamics) , phase (matter) , hydrostatic equilibrium , analytical chemistry (journal) , thermodynamics , crystallography , chemistry , metallurgy , alloy , physics , organic chemistry , chromatography , quantum mechanics
Diffusion of iron in DO 3 ordered Fe 76 Si 24 has been studied under hydrostatic pressure at 934 K. The diffusion coefficients were determined using the radiotracer technique with the implanted radioisotope 59 Fe and a precision grinding device for serial sectioning. The resulting activation volume of diffusion is ΔV = 1.48 × 10 −29 m 3 = 1.27Ω (Ω atomic volume). The large value of ΔV can be attributed to vacancy‐mediated Fe diffusion, in which divacancies or even larger vacancy clusters might be involved. This assumption is corroborated by positron annihilation experiments, which show a strong increase of the lifetime of trapped positrons in Fe 75 Si 25 at higher temperatures.