Calcium titanate

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Calcium titanate
CaTiO3 perovskite structure.png
Names
Other names
calcium titanium oxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.795
RTECS number XR2568666
Properties
CaTiO3
Molar mass 135.943 g/mol
Appearance white powder
Density 3.98 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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Infobox references

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[edit]

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][3]

Structure[edit]

Calcium titanate is obtained as orthorhombic crystals, more specifically perovskite structure.[4] 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.

Applications[edit]

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.[5]

See also[edit]

External links[edit]

References[edit]

  1. ^ a b c R. Robie, B. Hemingway, and J. Fisher, "Thermodynamic Properties of Minerals and Related Substances at 298.15K and 1bar Pressure and at Higher Temperatures," US Geol. Surv., vol. 1452, 1978.[1]
  2. ^ Pfaff, G. (1994). "Synthesis of calcium titanate powders by the sol-gel process". Chemistry of Materials. 6: 58. doi:10.1021/cm00037a013. 
  3. ^ Dunn, B.; Zink, J. I. (2007). "Sol–Gel Chemistry and Materials". Accounts of Chemical Research. 40 (9): 729. doi:10.1021/ar700178b. PMID 17874844. 
  4. ^ Buttner, R. H.; Maslen, E. N (1992). "Electron difference density and structural parameters in CaTiO3. In". Acta Crystallographica. 1992 (B48): 644–649. doi:10.1107/S0108768192004592. 
  5. ^ Heinz Sibum, Volker Günther, Oskar Roidl, Fathi Habashi, Hans Uwe Wolf, "Titanium, Titanium Alloys, and Titanium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a27_095