Phase relations for SrF2 TO 50 Kbars and 1900°C and its compression to 40Kbars at 25°C

Abstract The phase diagram of SrF2 to 50 Kbars and 1900°C, obtained primarily by differential thermal analysis (d.t.a.), is presented. In analogy to the isostructural compound CaF2, three solid phases, α, β, γ-SrF2, as well as the liquid field, have been located. Thermochemical data (dT/dP, ΔV, ΔS) of the α-β and α-γ boundaries, and the melting curve are given. A tentative phase diagram for the isostructural compound BaF2 is proposed. In addition, the first compression data for SrF2 to 40 Kbars are reported. The bulk modulus, its pressure derivative, and the Gruneisen constant of SrF2, CaF2 and BaF2 are compared.

[1]  I. Jackson Melting of some alkaline-earth and transition-metal fluorides and alkali fluoroberyllates at elevated pressures: A search for melting systematics , 1977 .

[2]  G. Kennedy,et al.  Compressibility of 27 halides to 45 kbar , 1971 .

[3]  O. Anderson,et al.  Equation for thermal expansivity in planetary interiors , 1967 .

[4]  D. Schuele,et al.  Pressure and temperature derivatives of the elastic constants of caF2 and BaF2 , 1968 .

[5]  M. W. Thomas Neutron diffraction evidence for anion sublattice disordering in alkali earth fluorides at high temperatures , 1976 .

[6]  P. Mirwald,et al.  Low‐friction cell for piston‐cylinder high‐pressure apparatus , 1975 .

[7]  A. D. Kirshenbaum,et al.  THE DENSITY OF MOLTEN METAL FLUORIDES IN THE RANGE OF 1600-2500 K , 1960 .

[8]  G. Kennedy,et al.  Investigation of phase transformations at elevated temperatures and pressures by differential thermal analysis in piston-cylinder apparatus , 1966 .

[9]  G. Kennedy,et al.  Compressibility of 18 metals to 45 kbar , 1970 .

[10]  G. Samara Pressure-Induced Phase Transitions in Solids: Ba F 2 , 1970 .

[11]  A. Singh,et al.  Compressibility of hexagonal selenium to 45 kbar , 1974 .

[12]  C. R. Masson,et al.  Melting points of inorganic fluorides , 1968 .

[13]  P. W. Bridgman Linear Compressions to 30,000 Kg/Cm, including Relatively Incompressible Substances , 1949 .

[14]  A. K. Singh,et al.  Compression of calcite to 40 KB , 1974 .

[15]  B. Yates,et al.  The low-temperature thermal expansion and vibrational properties of alkaline earth fluorides , 1967 .