A simple aqueous sol-gel route has been refined to prepare yttrium-doped ba
rium titanate powders. Thermal decomposition of the fabricated gel was stud
ied by means of DTA/TGA measurements. The precursor gel was intermediate ca
lcined at 600 degrees C, and the final synthesis products were characterize
d by IR spectroscopy, X-ray powder diffraction and scanning electron micros
copy. The barium titanate obtained from the calcination of the gel at 1300
degrees C was a tetragonal phase, and showed a positive temperature coeffic
ient of resistivity (PTCR) effect which depends on sample cooling rate duri
ng the final heat treatment. (C) 1999 Kluwer Academic Publishers.