Re-investigation of the La–Mg phase diagram

Thermodynamic and mechanical properties of lanthanum–magnesium phases from density functional theory

“…Of these six compounds, it is only LaMg 12 for which a definitive (fully occupied) structure remains in question. A more recent assessment of the La-Mg phase diagram may be found in Berche et al [28].…”

“…[2,[29][30][31][32][33][34]. Future alloy designs from computational thermodynamics via the CALPHAD approach [35] will likely rely upon DFT-predicted properties in the absence of experimental data [36][37][38][39]: careful validation of these properties against relevant experimental data is critical.…”

Phase Equilibria at 500 °C of the Mg-Gd-La System

“…3(c), the dark phase is La 5 Mg 41 while the grey and white phases are GdMg 5 and (Gd,La)Mg 3 , respectively. The La 5 Mg 41 phase, which was assumed by Berche et al [9] to be unstable below 600°C, was detected both in alloys #5 and #24, suggesting that La 5 Mg 41 exists stably at 500°C both in the ternary Mg-Gd-La and binary Mg-La alloys. This phase was detected by Giovannini et al [8] only in the samples annealed at 600°C for 125 h, but it was included in the 500°C isothermal section of the Mg-La-Y system constructed by them without further comments.…”

“…Figure 5 is the isothermal section at 500°C of the MgGd-La system, which was constructed according to the present work and the experimental information on the binary systems in literature. [4,9,10] The three-phase equilibrium of GdMg 5 + La 2 Mg 17 + La 5 Mg 41 in the Mg-rich corner is shown with dashed lines since it was not well determined in the present work. The intermediate Sm-type (delta) phase in the Gd-La binary system, which was reported by Gschneidner and Calderwood, [10] was not detected in the present work.…”

“…The LaMg 2 phase was regarded to exist only in the temperature range of 725-775°C. Later on, an additional intermediate phase of La 5 Mg 41 was found and suggested to form near 670°C by Giovannini et al [8] It should be noted that the La 5 Mg 41 phase was included in their constructed isothermal section at 500°C of the Mg-La-Y system though this phase was detected by them only in the samples annealed at 600°C for 125 h. Recently, Berche et al [9] re-investigated the La-Mg phase diagram in detail. The existence of the La 5 Mg 41 phase was confirmed and its eutectoid decomposition temperature was deduced to range from 577 to 600°C.…”