Phase relations of Zr(Fe Mn1−)2–H2 systems studied by XRD and isothermal-calorimetric measurement

Structural and Mössbauer spectroscopic study of cubic phase ZrFe2−xMnx hydrogen storage alloy

“…It is clear that the lattice volume Table 1 Lattice parameters and unit cell volume of ZrFe 2−x Mn x (x = 0.2, 0.4, 0.6, 0.8) increases with the increase in Mn content, which is due to the larger radii of Mn than that of Fe. The values of lattice constants are in good agreement with the published data [14] and were tabulated in Table 1. The SEM micrographs of ZrFe 2−x Mn x alloys are shown in Fig.…”

Crystal structure and hydrogen absorption of TixZr1−xMn2

“…Variation of relative partial molal heat of solution, H, and entropy, S, with hydrogen concentration are numerically shown in Table 4. The H values for ZrMn 2 -H 2 were in agreement with the calorimetric data [10] with correction of work by gaseous hydrogen taken into consideration. The absolute value of H slightly decreased with hydrogen concentration for ZrMn 2 , Ti 0.1 Zr 0.9 Mn 2 and Ti 0.2 Zr 0.8 Mn 2 .…”

“…The unit cell constants of the hydrides reported by Pourarian et al [7] are larger than those in the present work and those in other literatures [3,5]. This is also the case for the hydrides of Zr(Fe x Mn 1−x ) 2 [10]. In the study by Pourarian et al, SO 2 was admitted at a pressure of 2.4 kPa in order to poison the surface to confine hydrogen.…”

“…It has been found in our previous work [10] that Zr(Fe 0.2 Mn 0.8 ) 2 unexpectedly had lower equilibrium pressures than ZrMn 2 although the equilibrium pressures in the Zr(Fe x Mn 1−x ) 2 -H 2 systems essentially increased with the iron contents as a whole. The increasing order of the equilibrium pressures for the Zr(Fe x Mn 1−x ) 2 -H 2 systems before the ␣ (primary solid solution phase) → ␤ (hydride phase) transition somewhat differed from that after the transition.…”

Investigation of hydrogen absorption/desorption properties of ZrMn0.85−xFe1+x alloys

“…It can be seen that the crystal structures of the ZrMn 0.85 Fe and ZrMn 0.65 Fe 1.2 alloys were characterized as C14 (MgZn 2 ) type hexagonal structure with P6 3 /mmc space group, just like that of ZrMn 2 alloy [4]. When x was increased to 0.7, the alloy transformed into a cubic structure according to Suzuki et al [8] and Li and Nishimiya [11] who studied on the crystal structures of Zr(Fe x Mn 1−x ) 2 alloys. But in Kanematsu's [12] opinion, there also existed a hexagonal structure even if x was increased to 0.7.…”