CaF2-BaF2 phase diagram

Influence of a Second Cation (M = Ca2+, Mg2+) on the Phase Evolution of (BaxM1–x)F2 Starting from Amorphous Deposits

“…Instead, as monitored by TEM, crystalline BaF 2 separates from the amorphous (Ba 0.7 Mg 0.3 )F 2 phase at 320 °C, further at 450 °C, the ternary crystalline phase BaMgF 4 forms. These processes correctly reflect the phase diagram (Figure 2a) 9. However, the XRD measurements reveal that a solid solution phase with rutile‐type structure can form when the mixture contains around 15 % BaF 2 , which is a significantly larger share than expected according to the phase diagram (Figure 2b) 10.…”

Supercooling at Melt Growth of Single and Mixed Fluorite Compounds: Criteria of Interface Stability

“…As a result, after a primary crystallization of a continuous series of Ba 1-x Ca x F 2 fluorite solid solutions with a minimum in the liquidus curve at x < 0.5, during the cooling there occurs a high-T (at 900 o C) solid-state decomposition into a two-phase mixture of dilute CaF 2 and BaF 2 -based solid solutions (Chernevskaya, & Anan'eva, 1966;Wrubel et al, 2006;Zhigarnovskii & Ippolitov, 1969). The phase diagram of this system has been recently reviewed by Fedorov et al (2005) who showed it does not contain a continuous solid solution. Thus, on cooling the 70CaF 2 -30BaF 2 melt (mol%), a Ca 1-y Ba y F 2 solid solution ( -phase) solidifies as a primary phase, which at (1039 ± 5) o C reacts with the melt to form a second fluorite α-phase, Ba 1-x Ca x F 2 .…”

Glasslike Two-Level Systems in Minimally Disordered Mixed Crystals

“…The concentrations were measured at 8-10 places along the side of the samples via Raman scattering and the average values are given in Table I. The Ba 1ÿx Ca x F 2 samples showed significant variation over the sample length for greater than 2% CaF 2 , consistent with the onset of the miscibility gap [12]; while the Pb 1ÿx Ca x F 2 samples were inhomogeneous above about 4% CaF 2 , again consistent with the phase diagram showing segregation starting at 4 -6 mol% CaF 2 [13]. Laue backscattering measurements indicated that the samples are composed of few-mm single crystal domains with slight reorientations between neighboring crystals.…”