Laminated Modulation of Tricritical Ferroelectrics Exhibiting Highly Enhanced Dielectric Permittivity and Temperature Stability

Abstract

Ferroelectric materials with large dielectric response and high temperaturestability have found significant applications in advanced electronics and electrical power/storage equipment. The effective approaches explored up to now mainly focus on improving dielectric response by employing the phase instability caused by the ferroelectric transition. Nevertheless, one inherent shortcoming is that the enhancement of dielectric permittivity is at the expense of the deterioration of its temperature stability. Here, a strategy that successfully achieves both enhanced dielectric response as well as excellent temperature reliability (with ε r ≈ 2 × 10 4 from 30 to 85 °C) by designing a laminated structure of tricritical ferroelectrics (LTF) with successive Curie temperatures is proposed. Moreover, the improvement in dielectric performance triggers the temperature-stable energy-storage performance as well as electrocaloric property in LTF specimens. Further microstructure investigation and phase-field modeling reveal that these remarkable properties of laminated layers originate from the successive occurrence of tricritical transition with a nanodomain structure in a wide temperature range. The findings may shed a new light on developing advanced ferroelectrics with high performance and thermal reliability.

Enhancing the Energy Density of Tricritical Ferroelectrics for Energy Storage Applications

“…A recent investigation on the high-performance BaTiO 3 -based ceramics suggests that a large dielectric response with the maximum permittivity ε r > 20000 appeared at the Curie temperature of tricritical composition [7,8]. Further studies reveal that higher dielectric permittivities ( ε r = 45000 ~ 54000) can be achieved in the tricritical point of BTS and Ba(Ti 1− x Hf x )O 3 (BTH) ceramics [9,10,35]. The temperature-dependence of dielectric permittivity for BTS x -10BZN is shown in Figure 4.…”

Multifunctional barium titanate ceramics via chemical modification tuning phase structure

“…If stack them to one ceramic plate with laminated structure, each temperature scale will present giant ε r via superposition of high dielectric response around T C . As a result, a high ε r of ~2 × 10 4 is achieved from 30 to 85°C in the BTSn x /BTHf y laminated ceramic system, along with excellent temperature reliability, as shown in Figure 12E 211 . It is demonstrated that nanoscale polarization inhomogeneity presents in quasi‐quadruple point, which results in the flattening of Landau free energy profile.…”

“…E, ε r ‐ T curves for laminated Ba(Ti 1‐ x Sn x )O 3 /Ba(Ti 1‐ x Hf x )O 3 (BTSn x /BTHf y ) ceramics 211 . Reproduced with permission 211 . Copyright 2019, John Wiley & Sons.…”

Accelerated Search for BaTiO3‐Based Ceramics with Large Energy Storage at Low Fields Using Machine Learning and Experimental Design

“…For example, Gao et al synthesized Ba(Ti 0.895 Sn 0.105 )O 3 with an energy storage density of ≈55 mJ cm −3 at 20 kV cm −1 based on operating in the region of tricritical behavior in the phase diagram. This exceeds most of the ferroelectric materials at the same field strength . In the present study, we introduce several dopants into the BaTiO 3 prototype to search for solid solutions with enhanced energy storage density at a field of 20 kV cm −1 .…”