Synthesis of fine-particle titanates by the pyrolysis of oxalate precursors

Sekar, Amala M and Dhanaraj, G and Bhat, HL and Patil, KC (1992) Synthesis of fine-particle titanates by the pyrolysis of oxalate precursors. In: Journal of Materials Science: Materials in Electronics, 3 (4). pp. 237-239.

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Abstract

Fine-particle $MTiO_3$, where M = Ca, Sr, Ba or Pb, were prepared by the pyrolysis of $MTiO(C_20_4)_2\hspace^.4H_2O$ in the presence of a redox mixture containing $NH_4NO_3$ and oxalic acid dihydrazide at 350°C. The redox mixture, having a low ignition temperature, not only pyrolyses the oxalate precursor but also produces large quantities of gases, which results in a fine, foamy oxide product. The exothermicity of the redox reaction provides the heat required for the decomposition of the oxalate, and the gases evolved create the foamy nature of the product and help to dissipate the heat, which inhibits the sintering of $MTiO_3$. Metal titanate powders obtained by the pyrolysis of the oxalates are of submicrometre size and have a high surface area $(18-42 m^2g ^{- 1})$. The sintered $BaTiO_3$ and $PbTiO_3$ showed spontaneous polarization of 12 and 26 $\muCcm^{-2}$, respectively, for a field strength of $120 kVcm^{-1}$.

Item Type: Journal Article Copyright of this article belongs to Springer. Division of Physical & Mathematical Sciences > PhysicsDivision of Chemical Sciences > Inorganic & Physical Chemistry 09 Oct 2006 19 Sep 2010 04:32 http://eprints.iisc.ernet.in/id/eprint/8817