The Calcium–Strontium Metal Phase System

Abstract

The calcium-strontium phase system has been investigated in the liquid and solid state over the entire range of compositions. The liquidus and_ solidus curves were determined by differential thermal analysis whereas the solid state equilibria were studied by X-ray diffraction methods. Complete miscibility in both the liquid and solid state were observed with a minimum in the liquidus-solidus at 78 ± 2 weight % strontium and at 738°. Calcium, strontium and all calcium-strontium alloys exist in three crystalline modifications, face-centered cubic, hexagonal close-packed and body-centered cubic. There is a minimum in the b.c.c. h.c.p. transition, but the h.c.p. <=* f.c.c. transition in all alloys occurs at temperatures intermediate to the transition temperatures of the pure components. The variation of oo with atomic % at room temperature for f.c.c. alloys is linear in conformity with Vegard's law. At 415°the variation of both Oo and Co of the h.c.p. modification is linear with atomic per cent, for the calcium rich alloys; however, positive deviation from Vegard's law occurs with strontium-rich alloys. Positive deviation from Vegard's law also occurs in the strontium-rich b.c.c. alloys (615°).

Crystal structures and hydrogenation characteristics of Ca8(Al1−xNix)3 alloys

“…For the Rietveld refinement of the Ca 8 (Al 0.9 Ni 0.1 ) 3 alloy, the structure models for the Ca 8 Al 3 , Ca and NiAl phases were, respectively, taken from the reported structures [4,8,9]. We initially assumed that Ni atoms randomly occupy the Al sites in the Ca 8 Al 3 phase.…”

Thermodynamic Modeling of the Li-H and Ca-H Systems

“…Peterson and Fattore (Ref 20) suggested that a small amount of hydrogen induces the appearance of the c phase. Some researchers (Ref [21][22][23][24][25] suggested that this phase may be of hcp structure considering the allotropic transformation of pure Ca. In this work, the c phase is treated as a simple solution phase with hcp structure.…”

First-principles study of ternary fcc solution phases from special quasirandom structures

“…Prior to applying the ternary SQSs to the Ca-Sr-Yb system, the mixing behavior of the fcc phase in its constitutive three binaries was investigated through eight-atom binary fcc SQSs at three different compositions, namely, x = 0.25, 0.5, 28,29 to evaluate interaction parameters in Eq. ͑4͒ for each binary.…”