Chemical synthesis of barium zirconate titanate powder by an autocombustion technique

Abstract

A self-propagated combustion technique for the synthesis of zirconia-doped barium titanate (BZT) is reported. The technique involves autocombustion of a citrate-nitrate gel at relatively low temperature ( 150-200 "C). The product is obtained after calcination of the resulting ash at ca. 800 "C. The method is very simple, convenient, less explosive than conventional methods and is expected to be economic for large-scale production of fine (1.36 pm), homogeneous powders without any compositional fluctuation. The typical surface area of the calcined powder particles is found to be ca. 9.0 m2 g-', corresponding to an average particle size of 0.1 pm. The powder could be sintered up to 92-93% density at 1300 "C, which is significantly lower than that used for the powders prepared by conventional routes.

Free-Standing Lead Zirconate Titanate Nanoparticles: Low-Temperature Synthesis and Densification

“…Marinsek and co-workers have used this method to form a Ni−YSZ cermet anode . The synthesis of barium zirconate titanate powder with a particle size of about 1.36 μm was reported by Maiti et al, which involved autocombustion of a citrate nitrate gel route . The typical surface area of these particles was 9.0 m 2 /g, and they were sintered up to 92−93% density at 1300 °C.…”

New Synthesis of Ferrite–Silica Nanocomposites by a Sol–Gel Auto-Combustion

“…In the light of these considerations, great interest has attracted a very promising way proposed for the preparation of multicomponent oxide ceramic powders based on a sol-gel autocombustion process. Precursor gels are often prepared from an aqueous solution of the metal nitrates and an organic complexant such as citric acid (Roy et al, 1993;Chakraborty et al, 1994Chakraborty et al, , 1996Shafer et al, 1997;Yue et al, 1999), carboxylate azides (Ravindranathan, 1986(Ravindranathan, , 1987, urea (Kingaley & Patil, 1988), or glycine (Chick et al, 1990;Pederson et al, 1991) .…”

“…The citric acid plays two important roles: on one hand, it is the fuel for the combustion reaction; on the other hand, it forms complexes with metal ions preventing the precipitation of hydroxilated compounds; the nitrate ion is the burning oxidizer. Moreover, among the various complexants mentioned above, citrate gel appears to be the least explosive and, therefore, relatively more safe (Chakraborty & Maiti, 1996).…”

‘Ultra’-low-temperature sintering of PZT: A synergy of nano-powder synthesis and addition of a sintering aid

“…The first exotherm can be assigned to the decomposition of the metal complexes, and the second peak [for samples-(b) and (c)] can be attributed to the oxidation of the residual carbonaceous matter along with slow crystallization of the amorphous structure. 30 In the TGA plots (Fig. 4) of the as-burnt powders (after autocombustion), sample-(b) shows less than 1 wt% loss indicating complete reaction, whereas samples-(c) and (a) show around 68% and 15% weight loss, respectively indicating incomplete combustion during the autocombustion stage.…”