Size Effect on the Phase Transition in PbTiO₃ Fine Particles

Abstract

The finite size effect on the phase transition in PbTiO3 fine particles is described. Very small crystals with an average diameter of 14.2 nm were obtained by lowering the calcination temperature to 400° C. Raman scattering measurements of such fine particles were carried out to study the dependence of the phase transition temperature on the particle size. The X-ray diffraction pattern was also measured to study the tetragonality, c/a ratio. The results strongly suggest the presence of a critical size below which the ferroelectric state becomes unstable. The critical size determined by Raman measurements was 10.7 nm.

Tunable multiferroic properties in nanocomposite PbTiO3–CoFe2O4 epitaxial thin films

“…According to the literature, one would not expect to see a significantly reduced T C until the grain size decreases down to about 20 nm. 23 This is in clear contrast to the microstructure in our nanocomposite.…”

Size Dependence of Ferroelectric Properties of Epitaxial PbTiO₃ Nanoislands on Pt/SrTiO₃(100)

“…The growth temperature and pressure were 540-600 o C and 5.0Torr, respectively. (C 2 H 5 ) 3 PbO-n-CH 2 C(CH 3 ) 3 , Ti(O-i-C 3 H 7 ) 4 and O 2 were used as precursors and oxidant, respectively [13][14][15]. The surface morphology and piezoelectric properties were evaluated by atomic force microscopy (AFM) and piezoresponse force microscopy (PFM).…”

“…The size dependence was considered as extrinsic size effects derived from the clamping by substrates and 90 o domain wall movements [1][2][3]. Intrinsic size effects, in these reports, were not observed because the dimensions of islands fabricated by the top down methods were much larger than the size in which intrinsic size effects were observed in ultrafine particles [4][5][6]. On the other hand, ferroelectric islands with dimensions similar to the critical size of ultrafine particles have been successfully fabricated by the bottom up method [7][8][9][10].…”

Ferroelectric nanoparticles, wires and tubes: synthesis, characterisation and applications

“…nanoparticles, have 90 been widely investigated by researchers. 29,141,142,227 For example, the finite size-effect on the ferroelectric phase transitions in PbTiO3 nanoparticles were studied in the late '80s.…”

“…29,141,142 Park et al 29 first reported the decrease in TC and the increase in the tetragonal crystal 25 distortion of BaTiO3 nanoparticles with decreasing diameter (33 to 140 nm). The researchers also determined that the minimum critical diameter required for a ferroelectric phase transition in the nanoparticles was 37 nm.…”