METALLO-ORGANIC DECOMPOSITION SYNTHESIS AND CHARACTERIZATION OF FERROELECTRIC (PB_{1 −X}CA_X)TIO₃ Thin Films

Abstract

Synthesis of ferroelectric (Pb 1−x Ca x )TiO 3 (PCT) thin films over Pt/Ti/SiO 2 /Si substrates by metallo-organic decomposition (MOD) technique using a new chemical precursor route is described. The Ca composition dependent changes in the structural, dielectric and ferroelectric properties of the PCT films have been investigated. Typical tetragonal structure of the PCT films is evidenced with Ca ≤ 40% and at higher Ca concentration ∼50% a transformation to a pseudocubic structure is observed. Dependence of the ferroelectric properties on the Ca substitution is related to the combined effect of reduction in internal stress in the films, decrease in the grain size and dielectric anisotropy.

Dielectric and optical constants of nanostructured (Pb0.7Sr0.3)TiO3thin films suitable for high frequency devices

“…With an increase in annealing temperature to 750 • C, the grain size and surface roughness increase to 47 nm and 5.9 nm, respectively. The observed grain sizes are significantly smaller than that reported for the lead calcium titanate (PCT) thin film prepared by a similar technique [20], where the particle size was observed in the range 200-500 nm. The smaller grain size with Sr contents may be attributed to lower graingrowth rates due to the slower diffusion of Sr 2+ ions.…”