Dielectric relaxation and local domain structures of ferroelectric PIMNT and PMNT single crystals

Abstract

Dielectric relaxation properties of ternary Pb(In1/2Nb1/2)O3‐0.49Pb(Mg1/3Nb2/3)O3‐0.27PbTiO3 (PIMNT27) and binary Pb(Mg1/3Nb2/3)O3‐0.27PbTiO3 (PMNT27) single crystals have been investigated. The dielectric constant peak temperature Tm with frequency obeys the Vogel‐Fulcher (V‐F) law. The dielectric constants at temperatures above Tm can be described by the Lorenz‐type relationship. The fitting parameter δA and ΔTm of PIMNT27 are higher than those of PMNT27, indicating stronger relaxation in ternary PIMNT system. Local nanodomain structures were measured by the piezoelectric force microscopy (PFM). The average autocorrelation function technique was applied to quantify these nanoscale domain patterns. The PIMNT27 exhibits smaller size nanodomains and shorter mean local short‐range correlation length compared to PMNT27. The enhanced local disorder in PIMNT is related to the introduction of In3+ in PMNT system, which can enhance the disorder of B‐site ions. In addition, the evolution of local polarization rotation under a step‐increased tip dc voltage and the mean local short‐range correlation length <ξ> as a function of dc voltage were obtained for both PIMNT27 and PMNT27 single crystals, which are crucial parameters for the understanding of the relationship between dielectric relaxation and local domain structures in relaxor‐PbTiO3 systems.

Observation of Micro-Scale Domain Structure Evolution under Electric Bias in Relaxor-Based PIN-PMN-PT Single Crystals

“…The inset in Figure 2a demonstrates a well-fitted T m -f relation for the prepared sample using the V-F law. The fitting result gives a T f value of 466.3 K, which is not only higher than that (T f ~387 K) observed in the R-phase PMN-27PT single crystal but also higher than the T f value (T f ~432 K) obtained for the PIN-PMN-27PT single crystal with a lower PT composition [39]. It suggests that augmenting the composition of PbTiO 3 in the PIN-PMN-PT can enhance the static freezing temperature of the polarization fluctuation.…”

“…This lack of observable changes might be attributed to one of two reasons: (i) the electric driving force generated by the 3 V tip bias is insufficient to surmount the requisite energy barrier for domain switching, hence leading to the absence of domain switching, or (ii) the geometrical dimension induced by the 3 V tip bias is smaller than the critical dimension required for domain nucleation, causing the nucleated domains to switch back to their original state. According to the report on the domain structure and its dynamical behavior of the [001] C -oriented PIN-49PMN-27PT single crystals with R-phase, we found that some new domains formed when a small tip bias of 0.5 V was applied to the sample [39]. The results indicate that the PIN-PMN-33PT single crystals show better electric field stability than the PIN-PMN-27PT single crystals at the nanoscale, and this is consistent with the result that the former has a higher E c [39].…”

“…According to the report on the domain structure and its dynamical behavior of the [001]C-oriented PIN-49PMN-27PT single crystals with R-phase, we found that some new domains formed when a small tip bias of 0.5 V was applied to the sample [39]. The results indicate that the PIN-PMN-33PT single crystals show better electric field stability than the PIN-PMN-27PT single crystals at the nanoscale, and this is consistent with the result that the former has a higher Ec [39]. However, as the tip bias is further increased to 5 V, the By elevating the tip bias from 5 V to 7.5 V, the sizes of the small irregular domains experience significant growth due to polarization switching evoked by the electric field, as shown in Figure 5d,e.…”

Designing Monoclinic Heterophase Coexistence for the Enhanced Piezoelectric Performance in Ternary Lead-Based Relaxor Ferroelectrics

“…To quantify the frequency dispersion behavior, the maximum temperature of ε max ( T m ) around 473 K with Δ T m ≈ 10 K over frequency range of 10 2 to 10 6 Hz is fitted by the Vögel-Fulcher law , , where the activation energy U a of 33.5 meV and the static freezing temperature T f of about 467 K are achieved. It implies that the monoclinic PIN-PMN-PT holds the enhanced relaxation and predicts a strong PNR interaction. , …”

“…It implies that the monoclinic PIN-PMN-PT holds the enhanced relaxation and predicts a strong PNR interaction. 36,37 To explore the heterophase structure, internal energy, and temperature stability, we employ the unpolarized and polarized Raman spectroscopy in the cross-polarized VH: z ̅ (x,y)z and parallel-polarized VV: z ̅ (x,x)z geometries. Room temperature Raman spectra were shown in Figure S1(a) (see the Supporting Information, SI).…”