Nomenclature
CAS number: 12047-27-7
Barium titanium oxide (BaTiO
3); barium metatitanate.
BaO
3Ti; mol wt 233.19.
Ba 58.89%, O 20.58%, Ti 20.53%.
BaTiO
3.
Description and references
Usually prepd by calcining (at about 1300°)
an intimate mixture of titanium dioxide and barium carbonate. Prepn
from Ti oxalate and a barium compd: Lynd, Merker, US 2758911 (1956 to National Lead). Wet process by the addn of a titanium ester, such as tetrapropyl
titanate, to an aq soln of barium hydroxide: Flaschen, J. Am. Chem. Soc. 77, 6194 (1955).
Prepn of high purity material by ignition of barium titanyloxalate:
Clabaugh et al., J. Res. Natl.
Bur. Stand. 56, 289 (1956). Prepn by ignition
of Ba and Ti alcoholates in an organic solvent: DiVita, Fischer, US 2985504 (1961 to U.S. Dept.
of the Army).
Properties
Exists in five cryst modifications. The tetragonal
form (obtained by the wet process) appears to have the most desirable
electric properties and is described here: d 6.08. mp 1625°. Curie point 120°. Has ferroelectric and piezoelectric
properties. Becomes permanently polarized when exposed to high voltage
direct current, provided the temperature is never allowed to rise
above Curie pt. Has high dielectric properties which can be influenced
by temp, voltage, and frequency.Use
In electronic devices, e.g., as voltage-sensitive
dielectric in so-called dielectric amplifiers, in computer elements,
magnetic amplifiers, memory devices.