Solubility of deuterium and hydrogen in fcc iron at high pressures and temperatures

PHYSICAL REVIEW MATERIALS. 2019. Vol. 3. No. 11. Article 113604.

Antonov V., Gurev V., Kulakov V., Kuzovnikov M., Sholin I., Zuykova V.

An isobar x(T) of deuterium solubility in iron is constructed at P = 6.3 GPa and 100 ≤ T ≤ 800 °C based on the results of thermal desorption analysis of FeDx samples produced by quenching under high D2 pressure to the temperature of liquid nitrogen. The experiment confirms the value of x = 0.64 at T = 715 °C proposed previously in a neutron diffraction work [Machida et al., Nature Commun. 5, 5063 (2014)] for γ iron deuteride under the assumption that deuterium atoms occupy both octa- and tetrahedral interstices in its fcc metal lattice. An estimate of ΔV/x = 2.2 Å3/atom D made in that work for the deuterium-induced volume expansion ΔV(x) of fcc iron is also confirmed. To prove that the absorption of protium leads to a similar volume expansion, we constructed an isotherm x(P) of hydrogen solubility in fcc iron.

Keywords: High pressures, Phase diagrams, Высокие давления, фазовая диаграмма, iron deuteride, дейтерид железа