Distinctive contributions to dielectric response of relaxor ferroelectric lead scandium niobate ceramic system

Abstract

Dielectric properties of normalPbfalse(Sc1/2Nb1/2false)O3 (PSN) ceramic system, prepared from mechanochemically activated powder, were studied in a broad temperature range of 150–750 K. Various distinctive contributions were recognized in the detected reponse. A typical relaxor dispersive maximum, accompanied by a sharp dielectric anomaly showing a hysteretic behavior, reveals that developed disordered PSN ceramics undergoes a spontaneous relaxor‐to‐ferroelectric phase transition, even in zero electric field. At high temperatures, a strong dielectric dispersion due to the Maxwell–Wagner‐type contributions of interface layers between the sample and contacts governs the detected response above 500 K. The intrinsic high‐temperature dielectric response follows, however, the universal scaling rather than the classical mean‐field behavior. The latter can be rejected on the confidence level better than 99% according to the F‐test and, furthermore, the analysis revealed a critical exponent that indicates a critical behavior associated with universality classes typically found in spin glasses. Finally, nearly perfect agreement between the fitting parameter of Tc=372±3K (obtained by analysis in the interval of 600–775 K) and the experimentally detected value of this relaxor‐to‐ferroelectric phase transition temperature manifests that the low‐temperature fingerprint behavior can be observed at much higher temperatures, well above the dispersive relaxor dielectric maximum.

Controlling Dielectric and Relaxor-Ferroelectric Properties for Energy Storage by Tuning Pb0.92La0.08Zr0.52Ti0.48O3 Film Thickness

“…In conventional thick ferroelectric films, D1 and D2 are negligible, and thus, only P is presented. For thin relaxor-ferroelectric films with the thickness less than 1000 nm, the leakage current ( D1 ) ,, and dielectric capacitive current ( D2 ) , become significant since both are inversely proportional to the film thickness. For relaxor-ferroelectric thin films, the nanoscale grain structure and defects make them highly susceptive to leakage current, and high ε r values make the dielectric capacitance significant (with C 0 = ( ε 0 ε r )/d ).…”

“…It should be noted that the polarization P in the P−E curves shown in Figure 2 and Supporting Information Figure S1a should be more precisely referred to as electric displacement D, which consists of three contributions: electric conductivity D1, dielectric capacitance D2, and domain switching ferroelectric polarization P. 22 In conventional thick ferroelectric films, D1 and D2 are negligible, and thus, only P is presented. For thin relaxor-ferroelectric films with the thickness less than 1000 nm, the leakage current (D1) 8,20,21 and dielectric capacitive current (D2) 22,23 become significant since both are inversely proportional to the film thickness. For relaxor-ferroelectric thin films, the nanoscale grain structure and defects make them highly susceptive to leakage current, and high ε r values make the dielectric capacitance significant (with C 0 = (ε 0 ε r )/d).…”

“…Here we report the study of energy storage properties of high-quality epitaxial PLZT (8/52/48) thin films (from ∼100 to 1000 nm) grown by pulsed laser deposition (PLD), a potentially scalable technique. These PLZT films contain substatially fewer crystallographic defects, especially a reduction in the number of large-angle grain boundaries. − However, since the thickness is near the scale of grain boundaries, the current passing through these PLZT films contains significant leakage current due to the finite electric conductivity ,, and capacitive charge–discharge current due to the linear dielectric permittivity, , which are superimposed with the conventional polarization measurement due to relaxor-ferroelectric domain switching as observed in thicker films. The relative contributions from each component should depend on the film thickness.…”

Unusual structural-disorder stability of mechanochemically derived-Pb(Sc0.5Nb0.5)O3

“…For more details regarding this phase transition at B97 1C, we refer to the complete analysis of the dielectric properties of MA1000 ceramics reported in our previous study. 36 Note that in PSN single crystals the relaxor-to-ferroelectric phase transition was also observed at B97 1C. 34,35 Similar e-T behaviour was obtained for all MA-derived samples from Table 1.…”

“…The indexed peaks of the perovskite phase are shown in brackets (ICSD #80922). 36 Note that in PSN single crystals the relaxor-to-ferroelectric phase transition was also observed at B97 1C. Fig.…”