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Calcium titanate

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Calcium titanate
Names
Other names
calcium titanium oxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.795 Edit this at Wikidata
RTECS number
  • XR2568666
UNII
  • InChI=1S/Ca.3O.Ti/q+2;;2*-1; checkY
    Key: AOWKSNWVBZGMTJ-UHFFFAOYSA-N checkY
  • InChI=1/Ca.3O.Ti/q+2;;2*-1;/rCa.O3Ti/c;1-4(2)3/q+2;-2
    Key: AOWKSNWVBZGMTJ-SLQOSCGQAQ
  • [Ca+2].[O-] [Ti]([O-])=O
Properties
CaTiO3
Molar mass 135.943 g/mol
Appearance white powder
Density 4.1 g/cm3
Melting point 1,975 °C (3,587 °F; 2,248 K)
Boiling point 3,000 °C (5,430 °F; 3,270 K)
insoluble
Hazards
Lethal dose or concentration (LD, LC):
>1200 mg/kg (oral, rat)
Thermochemistry
93.64 J/mol·K [1]
-1660.630 kJ/mol [1]
-1575.256 kJ/mol [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Calcium titanate is an inorganic compound with the chemical formula CaTiO3. As a mineral, it is called perovskite, named after Russian mineralogist, L. A. Perovski (1792-1856). It is a colourless, diamagnetic solid, although the mineral is often coloured owing to impurities.

Synthesis

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CaTiO3 can be prepared by the combination of CaO and TiO2 at temperatures >1300 °C. Sol-gel processes has been used to make a more pure substance, as well as lowering the synthesis temperature. These compounds synthesized are more compressible due to the powders from the sol-gel process as well and bring it closer to its calculated density (~4.04 g/ml).[2]

Structure

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Calcium titanate is obtained as orthorhombic crystals, more specifically perovskite structure.[3] In this motif, the Ti(IV) centers are octahedral and the Ca2+ centers occupy a cage of 12 oxygen centres. Many useful materials adopt related structures, e.g. barium titanate or variations of the structure, e.g. yttrium barium copper oxide.[citation needed]

Applications

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Calcium titanate has relatively little value except as one of the ores of titanium, together with several others. It is reduced to give titanium metal or ferrotitanium alloys.[4]

See also

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References

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  1. ^ a b c Robie, R. A.; Hemmingway, B. S.; Fisher, J. R. (1978). "Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar pressure and at higher temperature" (PDF). Geol. Surv. Bull.: 1452. Bibcode:1978BUSGS.....1452R. doi:10.3133/b1452.
  2. ^ Dunn, Bruce; Zink, Jeffrey I. (September 2007). "Sol–Gel Chemistry and Materials". Accounts of Chemical Research. 40 (9): 729. doi:10.1021/ar700178b. PMID 17874844.
  3. ^ Buttner, R. H.; Maslen, E. N. (1 October 1992). "Electron difference density and structural parameters in CaTiO3". Acta Crystallographica Section B. 48 (5): 644–649. doi:10.1107/S0108768192004592.
  4. ^ Sibum, Heinz; Güther, Volker; Roidl, Oskar; Habashi, Fathi; Wolf, Hans Uwe (2000). "Titanium, Titanium Alloys, and Titanium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a27_095. ISBN 978-3-527-30673-2.
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