Finite-size effects in antiferroelectric nanoparticles

Abstract

We study the size dependence of the antiferroelectric-to-paraelectric phase transition in ultrafine particles of PbZrO 3 (with x-ray domain size down to ≈30 nm) prepared by the sol-gel method. The phase transition was investigated by means of dielectric and thermal measurements. The nature of the particle size dependence of various properties of antiferroelectric PbZrO 3 was found to be generally similar to that of typical 'displacive' ferroelectrics such as PbTiO 3 and BaTiO 3 . In both cases, a size-induced structural distortion towards the high-symmetry paraelectric phase appears to dictate the behaviour of the nanoparticulate system. Nanoparticles of 'order-disorder' systems such as NaNO 2 behave in a markedly different manner. With decreasing particle size, we observe an increasing deviation of the dielectric response from the Curie-Weiss behaviour. Certain physical situations that may lead to the observed smearing out of the transition in nanoparticles of PbZrO 3 and PbTiO 3 are discussed.

Size dependence of nanostructures: Impact of bond order deficiency

“…22 leads to an estimation of the critical radius K C ¼ 3.5, which agrees with the value we determined recently (R C w 1.25 nm) [393]. For the smallest MgB 2 crystals, the relative Bragg intensities of the allowed reflections can only be successfully matched during Rietveld refinement by introducing statistically distributed B-vacancies, with the refined value falling from 1 to 2/3.…”

“…Fig. 21 shows the T C suppression of ferroelectric PbTiO 3 [243], SrBi 2 Ta 2 O 9 [339], BaTiO 3 [392] and anti-ferroelectric PbZrO 3 [393] nanosolids. For ferroelectric and superconductive nanosolids, T C ¼ 0 K occurs at V vac ¼ V C , which means that K C corresponds not to T C ¼ 0 K, but to a value that is much lower than room temperature.…”

Enhancement of Mechanical Properties of Polyamide Hexaglycol by Dispersion of TiO2 Nanofiller

“…), nonmetal oxide (SiO 2 ), and others (SiC) [9][10][11][12][13][14]. The selection of nanoparticle filler depends on the desired thermal, mechanical, and electrical properties of the nanocomposites [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The aim of this research was to study the effect of the weight percent of TiO 2 anatase nanofiller particles on the hardness, tensile strength, and creep at room termperature of nano TiO 2 / PAHG polymer matrix composite.…”

Dielectric function of antiferroelectric thin films

“…Chattopadhyay et al [9] have studied the size dependence of the AFE-toparaelectric phase transition in ultrafine particles of PbZrO 3 with X-ray domain size down to nearly 30 nm. The phase transition was investigated by means of dielectric and thermal measurements.…”