Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Mar 12;14(1):6017.
doi: 10.1038/s41598-024-55402-0.

Titanate-based high-entropy perovskite oxides relaxor ferroelectrics

Ketkaeo Bunpang  1   2 , Suparat Singkammo  3 , David P Cann  4 , Natthaphon Raengthon  5   6   7
Affiliations

Titanate-based high-entropy perovskite oxides relaxor ferroelectrics

Ketkaeo Bunpang et al. Sci Rep. .

Abstract

Different combinations of monovalent and trivalent A-cations in high-entropy perovskite oxides (HEPOs) were investigated. The multicomponent (A'0.2A″0.2Ba0.2Sr0.2Ca0.2)TiO3 (A' = Na+, K+, A″ = Bi3+, La3+) perovskite compounds were successfully synthesized by solid-state reaction method persisting average cubic perovskite phase. The trivalent cation exhibited distinct effects on local structure, dielectric properties and relaxor ferroelectric behavior. Highly dense ceramics (> 95%), high dielectric constant (~ 3000), low dielectric loss (~ 0.1), and relaxor ferroelectric characteristics were obtained in the compound containing Bi3+. The La3+ containing compounds revealed lower dielectric constant, higher dielectric loss and linear dielectric behavior. The effect of monovalent cation on the dielectric properties was minimal. However, it affected relaxor ferroelectric behavior at elevated temperatures and conduction behavior at high temperatures. The (K0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3 ceramic maintained the relaxor ferroelectric behavior with low PREM at high temperatures suggesting more stable relaxor ferroelectric characteristics than that of the (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3. Moreover, between these two compounds, the homogeneous electrical characteristics could be obtained from the compound consisting of K + and Bi + at A-site. This study suggests that tuning the chemical composition, particularly choosing appropriate combination of mono/trivalent cations in high entropy perovskite oxides, could be the effective approach to develop high-performance relaxor ferroelectrics with the desired properties.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Rietveld refinement analysis of synchrotron X-ray diffraction patterns for (a) NB, (b) KB, (c) NL, and (d) KL ceramics (e) Raman spectra of NB, KB, NL, and KL ceramics.
Figure 2
Figure 2
Change in (a) linear shrinkage (%) and (b) density and (c) relative density (%) of NB, KB, NL, and KL ceramics.
Figure 3
Figure 3
SEM images of (a) NB, (b) KB, (c) NL, and (d) KL ceramics.
Figure 4
Figure 4
Temperature dependent dielectric responses at various frequencies of (a) NB, (b) KB, (c) NL, and (d) KL ceramics.
Figure 5
Figure 5
Relationship between ln(1/εr − 1/εm) and ln(T − Tm) measured at 100 kHz of (a) NB and (b) KB ceramics. The red solid lines are the fit to the Modified Curie–Weiss law.
Figure 6
Figure 6
Polarization–Electric field (P-E) hysteresis loops at different applied electric field ranging from 10 kV/cm to 80 kV/cm of (a) NB, (b) KB, (c) NL, and (d) KL ceramics.
Figure 7
Figure 7
(a) P-E hysteresis loops, (b) relation between PMAX, PREM and composition, (c) relation between EC and composition, (d) relation between WREC, WLOSS and composition, and (e) relation between ŋ and composition of NB, KB, NL, and KL ceramics at 50 kV/cm.
Figure 8
Figure 8
Temperature dependence on P-E hysteresis loops of (a) NB and (b) KB ceramics measured under an electric field of 50 kV/cm and a frequency of 1 Hz.
Figure 9
Figure 9
Complex impedance plot between the imaginary part (Z″) and the real part (Z′) of (a) NB and (b) KB ceramics in the temperature range of 400 °C–500 °C.
Figure 10
Figure 10
Frequency dependence of the imaginary part of impedance (Z″) and electrical modulus of (a) NB and (b) KB ceramics in the temperature range of 400 °C–500 °C.
Figure 11
Figure 11
Arrhenius plot of relaxation time (τ) for (a) NB and (b) KB ceramics in the temperature range of 400 °C–500 °C.
See this image and copyright information in PMC

References

    1. Jayakrishnan AR, et al. Are lead-free relaxor ferroelectric materials the most promising candidates for energy storage capacitors? Prog. Mater. Sci. 2023;132:101046. doi: 10.1016/j.pmatsci.2022.101046. - DOI
    1. Yang L, et al. Perovskite lead-free dielectrics for energy storage applications. Prog. Mat. Sci. 2019;102:72–108. doi: 10.1016/j.pmatsci.2018.12.005. - DOI
    1. Tong X-Y, et al. Enhanced energy storage properties in Nb-modified Bi0.5Na0.5TiO3–SrTiO3 lead-free electroceramics. J. Mater. Sci. Mater. Electron. 2019;30:5780–5790. doi: 10.1007/s10854-019-00876-2. - DOI
    1. Zhang M-H, et al. High energy storage capability of perovskite relaxor ferroelectrics via hierarchical optimization. Rare Met. 2022;41:730–744. doi: 10.1007/s12598-021-01869-z. - DOI
    1. Sarkar A, Breitung B, Hahn H. High entropy oxides: The role of entropy, enthalpy and synergy. Scripta Mater. 2020;187:43–48. doi: 10.1016/j.scriptamat.2020.05.019. - DOI