Dielectric and ferroelectric properties of highly oriented (Pb,Nb)(Zr,Sn,Ti)O3 thin films grown by a sol-gel process

Abstract

Antiferroelectric (Pb,Nb)(Zr,Sn,Ti)O 3 thin films were deposited via a sol-gel process on LaNiO 3-coated silicon substrates. Films showed a strong ͑001͒ preferred orientation upon annealing at 500-700°C for 30 min. The dependence of electrical properties on film thickness has been studied, with the emphasis placed on field-induced phase switching from the antiferroelectric to the ferroelectric state. The decrease of film thickness led to an increase of the phase-switching field along with the appearance of remanent polarization. However, the dielectric constant and maximum polarization decreased with the reduction of film thickness. Saturation polarization was 35 C/cm 2 , which is equal to that observed in bulk samples.

Dielectric function of antiferroelectric thin films

“…1) could explain the experimental data of PbZrO 3 thin films or PbZrO 3 nanoparticles. The obtained results are in good agreement with the behaviour of the dielectric function in AFE PbZrO 3 nanoparticles obtained by Chattopadhyay et al [9] and by Jiwei et al [11] for PNZST thin films. The behaviour of the dielectric constant for this case is similar to the dielectric behaviour of FE PbTiO 3 and BaTiO 3 thin films obtained experimentally [4 -6] or theoretically [14]: With a decrease in the film thickness or the particle size, c T decreases, max e decreases, and the peaks become increasingly broader.…”

“…A broadened dielectric anomaly means that the phase transition occurs over a wider temperature range. Such a broad phase transition was also obtained experimentally in AFE thin films [9,11,12] and FE thin films [4 -6, 8, 14]. The explanation of the broadened peak can be the greater damping effects in thin films compared to the bulk case [22] what is in agreement with the experimental data of Fu et al [23].…”

“…The decrease of film thickness led to an increase of the phase-switching field along with the appearance of remanent polarization. However, the dielectric constant and maximum polarization decreases with the reduction of film thickness [11].…”

“…The lower dielectric constant in comparison to the bulk is a typical property of all thin films and is obtained for FE [4-6, 8, 14] and AFE [9,11,12] thin films. (ii) Secondly, the peaks become progressively broader as the film becomes thinner.…”

Asymmetry of domain forward switching and multilevel relaxation times of domain backswitching in antiferroelectric Pb0.99Nb0.02(Zr0.84Sn0.12Ti0.04)0.98O3 thin films

“…The loop appears similar to that from other ferroelectric material in agreement with previous reports. 3,11 As the film thickness is reduced to 90 nm, the loop at negative fields on the top electrode remains, but half of the loop at positive fields is lost, as shown in Fig. 1.…”