Structure of Barium Titanate at Elevated Temperatures

Edwards, James W.; Speiser, R.; Johnston, Herrick L.

doi:10.1021/ja01150a149

Cited by 73 publications

(51 citation statements)

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“…In addition, the unit formula volume of the cubic perovskite of SrSiO 3 is about 3.1 or 2.5% smaller than that of its 6H-type perovskite polymorph at about 25 GPa (experimental) or 32 GPa (theoretical), respectively, as shown in Figures 4 and 5. The volume difference between the 3C and the 6H perovskite polymorphs of SrSiO 3 is also in good agreement with that of the transition metal oxides such as BaRuO 3 (∼2.9%; Zhao et al 2007;Jin et al 2008), BaTiO 3 (∼2.8%; Edwards et al 1951;Akimoto et al 1994), and SrMnO 3 (∼3.5%; Kriegel and Preuβ 1996;Belik et al 2011). It proposes that, if they have a larger tolerance factor than unity, both of the main group oxides and the transition metal oxides comply with similar crystal chemistry criteria, and show a similar phase transformation sequence from the face-sharing hexagonal perovskite polytypes to the corner-sharing 3C-type perovskite polymorph under high pressures.…”

Section: Discussionsupporting

confidence: 75%

Cubic perovskite polymorph of strontium metasilicate at high pressures

Xiao

Zhou

Liu

et al. 2013

American Mineralogist

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By using a diamond-anvil cell (DAC) with laser heating technology, a cubic perovskite polymorph of SrSiO 3 has been synthesized at ∼38 GPa and 1500-2000 K for the first time. The P-V data of this new phase give ambient temperate elastic constants of V 0 = 49.18(5) Å 3 , K 0 = 211(3) GPa, respectively, when they are fitted against the Birch-Murnaghan equation of state with a fixed K 0 ′ at 4. On decompression, the SrSiO 3 cubic perovskite phase becomes unstable at ∼6.2 GPa and disappears completely at ∼4.7 GPa. The transformed product can be considered as an amorphous phase with a minor amount of small sized crystals in the amorphous matrix. First principle calculations predicted structural properties of both the cubic and the six-layer-repeated hexagonal perovskite polymorphs of SrSiO 3 in good agreement with experimental results. The experimental and theoretical results indicate that the larger Sr 2+ cation can substitute the Ca 2+ cation and enter into the lattice of the cubic perovskite phase of CaSiO 3 at lower mantle conditions with only a small lattice strain. These results indicate that Sr can be hosted in cubic perovskite CaSiO 3 found as inclusions in diamonds originating from the lower mantle.

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Section: Discussionsupporting

confidence: 75%

Cubic perovskite polymorph of strontium metasilicate at high pressures

Xiao

Zhou

Liu

et al. 2013

American Mineralogist

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“…17) For BaTiO 3 , the electronic structures of the cubic phase at 474 K and the tetragonal phase at 350 K are simulated using the lattice parameter measured at each temperature. 18,19) The cluster model for the cubic phase is similar to the one shown in Fig. 2(a), but the model used for the tetragonal phase is constructed as shown in Fig.…”

Section: Cluster Modelsmentioning

confidence: 99%

“…They are calculated for cubic ATiO 3 (A=Ca, Sr, Ba), by using the experimentally determined lattice parameters for each oxide in the cubic state. [16][17][18] For comparison, the calculated results of tetragonal BaTiO 3 at 350 K are included in Fig. 13.…”

Section: Chemical Bond Strengthmentioning

confidence: 99%

Modification of Local Electronic Structures Due to Phase Transition in Perovskite-Type Oxides, SrBO<SUB>3</SUB> (B=Zr, Ru, Hf)

2004

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The local electronic structures are simulated for a perovskite-type oxide with four polymorphous phases, SrZrO 3 , using the DV-X molecular orbital method. It is found that a series of phase transitions occurs at certain temperatures so as to retain not only the Zr-O bond strength, but also the Sr-O bond strength, by the tilting of ZrO 6 octahedra and the attendant accommodation to the Zr-O and the Sr-O interionic distances. The occurrence of such smart phase transitions is observed in other perovskite-type oxides, SrRuO 3 and SrHfO 3 . Another type of phase transition occurs by the cooperative ionic displacements along the [100] direction in BaTiO 3 . The differences in the local chemical bond are discussed between the two types of phase transitions.

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“…v is the specific volume of Pt, v = 4.64056 x 10 -2 + 6.0757 • 10 -7 T(K) + 4.675 x 10-1~ where the thermal expansion of pure Pt is taken from Waseda et al (1975) and Edwards et al (1951).…”

Section: V2(t)-vdr)mentioning

confidence: 99%

The partial molar volume of Fe₂O₃ in multicomponent silicate liquids and the pressure dependence of oxygen fugacity in magmas

et al. 1982

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ABSTRACT. Density measurements of eight silicate liquids containing substantial amounts of Fe203 have been made over a range of 250 ~ These have been combined with published density measurements on multicomponent silicate liquids to yield (by multiple regression) partial molar volumes of SiO2, TiO2, A1203, Fe2Oa, FeO, MgO, CaO, Na20, and K20. The data on Fe203-liquids are neither precise nor abundant enough to show #liq a compositional dependence of --Fe20~. In a liquid of constant composition and temperature, the pressure dependence of the oxygen fugacity is given bywhich, if AV is independent of pressure, necessitates an increase info2 with increasing pressure of about 1 log~0 unit for 10 kbars.Combining an equation relating oxygen fugacity to composition, T, and Fe203 at 1 bar (Sack et al., 1980) with the results for partial molar volumes, the oxygen fugacity of any magma can be calculated as a function of P and T. If basic magmas have their Fe203/FeO set in the source regions, and ascend isochemically, then the calculated oxygen fugacities in the mantle increase as pressure increases and silica activity decreases. A P-T grid has been constructed to show the calculated oxygen fugacities in a source region which has equilibrated with some common lava types, based on their FeO and Fe203 contents.DENSITY measurements of a variety of silicate liquids were used by Bottinga and Weill (1970) to derive partial molar volumes of oxide components and their temperature dependence. Since then ternary and multicomponent silicate liquids containing TiO2 have been measured and estimates of the partial molar volumes of the components SiO2, TiO2, A1203, FeO, MgO, CaO, Na20, and K20 were given by Nelson and Carmichael (1979). Although many of the density measurements of * Permanent address: Beijing College of Geology, Beijing, China. Copyright the Mineralogical SocietyFeO-containing systems report small amounts of Fe203 (e.g. Henderson, 1964;Shiraishi et al., 1978) the concentrations were so small that Bottinga and Weill constrained its volume in silicate liquids by analogy to that of crystalline Fe203 (hematite).This paper reports on the density measurements of Fe203-containing liquids, and gives estimates of the partial molar volumes of the nine oxide components most abundant in natural silicate liquids. The effect of pressure on oxygen fugacity in an isochemical silicate liquid can be calculated by making simple assumptions about the partial molar oxide compressibilities, and is used to illustrate the conditions of equilibration of various basic magmas with a mineral assemblage in the mantle.Experimental techniques. The apparatus used for the density determination is similar to that described by Bockris et al. (1956). It consists of a Pt/Rh-wound resistance furnace and temperature controller that operates in the range of 500 to 1600 ~ The furnace is mounted on a hydraulic jack so that it can be raised and lowered, with the distance measured on a micrometer dial gauge. A concrete platform mounted above the furnace supports ...

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Structure of Barium Titanate at Elevated Temperatures

Cited by 73 publications

References 0 publications

Cubic perovskite polymorph of strontium metasilicate at high pressures

Cubic perovskite polymorph of strontium metasilicate at high pressures

Modification of Local Electronic Structures Due to Phase Transition in Perovskite-Type Oxides, SrBO<SUB>3</SUB> (B=Zr, Ru, Hf)

The partial molar volume of Fe₂O₃ in multicomponent silicate liquids and the pressure dependence of oxygen fugacity in magmas

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Structure of Barium Titanate at Elevated Temperatures

Cited by 73 publications

References 0 publications

Cubic perovskite polymorph of strontium metasilicate at high pressures

Cubic perovskite polymorph of strontium metasilicate at high pressures

Modification of Local Electronic Structures Due to Phase Transition in Perovskite-Type Oxides, SrBO<SUB>3</SUB> (B=Zr, Ru, Hf)

The partial molar volume of Fe2O3 in multicomponent silicate liquids and the pressure dependence of oxygen fugacity in magmas

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The partial molar volume of Fe₂O₃ in multicomponent silicate liquids and the pressure dependence of oxygen fugacity in magmas