Enhanced Electrocaloric Effect in Sr2+-Modified Lead-Free BaZrxTi1–xO3 Ceramics

Jian, Xiaodong; Lü, Biao; Li, Dandan; Yao, Yingbang; Tao, Tao; Liang, Bo; Lin, Xiao; Guo, Jinhong; Zeng, Yijiang; Lu, Sheng‐Guo

doi:10.1021/acsami.9b04036

Cited by 44 publications

(13 citation statements)

References 41 publications

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“…Inspired by the fact that the addition of Sr can either reduce T d to a certain degree , or enlarge P max , ,, we anticipate that changing the amount of Sr in the mixture is an efficient method to lower the T d of [Bi 0.5 (Na 0.72 K 0.18 Li 0.1 ) 0.5 ]TiO 3 (BNKLT) ceramics meanwhile obtaining a large ECE. Herein, we designed a {[Bi 0.5 (Na 0.72 K 0.18 Li 0.1 ) 0.5 ] 1– x Sr x }TiO 3 (BNKLS x T) ceramic material system and investigated its ECE response with the variation of Sr content.…”

Section: Introductionmentioning

confidence: 99%

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Zhang

Zhao

Zheng

et al. 2020

ACS Appl. Mater. Interfaces

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The electrocaloric effect (ECE) is significantly critical for environmentally friendly cooling technologies to replace vapor compressionbased refrigeration. Lead-free bismuth sodium titanate-based ferroelectrics have attracted considerable attention because of their depolarization process, which can induce a high ECE. However, their high depolarization temperature (T d ) disobeys the principle of room temperature (RT) cooling. Considerable efforts have been devoted to the shift of T d to near RT via chemical doping, while the corresponding ferroelectric properties of the materials are sacrificed. Herein, we design a relaxor ferroelectric {[Bi 0.5 (Na 0.72 K 0.18 Li 0.1 ) 0.5 ] 1−x Sr x }TiO 3 (BNKLS x T) ceramic system which shows a decreased T d toward RT, and a high ECE (adiabatic temperature change of 2.51 K and electrocaloric coefficient of 0.386 K mm kV −1 ) is achieved when the measurement temperature approaches the T d . This high ECE performance outperforms most reported lead-free ceramics and even behaves better than 0.9Pb(Mg 1/3 Nb 2/3 )O 3 -0.1PbTiO 3 ceramics. The superior ECE behavior is ascribed to the enhanced maximum polarization (P max ) resulting from the addition of Sr and the existence of the depolarization process. Piezoresponse force microscopy results verify that the increased P max originates from the decreased domain size and the increased density of the domain in BNKLS x T. This work not only offers us an attractive lead-free ferroelectric material for ECE coolers but also opens a new direction toward the rational design of ceramics for ECE.

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Section: Introductionmentioning

confidence: 99%

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Zhang

Zhao

Zheng

et al. 2020

ACS Appl. Mater. Interfaces

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“…The extracted polarization from the P – E hysteresis loops, obtained using a parallel-plate capacitor configuration, is only the projected polarization along the electric field, whereas the direct measurement represents the material’s true polarization. The higher value of the ECE by the indirect method at 403 K may be due to an extra contribution of the smaller polar regions to the polarization along the electric field, which was possible when an optimum thermal energy was available for the sluggish polar regions to respond by orientation . However, a good agreement in Δ T measured by direct and indirect methods was found in many cases. , …”

Section: Resultsmentioning

confidence: 90%

“…The higher value of the ECE by the indirect method at 403 K may be due to an extra contribution of the smaller polar regions to the polarization along the electric field, which was possible when an optimum thermal energy was available for the sluggish polar regions to respond by orientation. 60 However, a good agreement in ΔT measured by direct and indirect methods was found in many cases. 12,53 3.5.…”

Section: Ec Study By a Direct Methodmentioning

confidence: 96%

Excellent Electrocaloric and Energy Storage Capabilities in (Na_0.8K_0.2)_0.5Bi_0.5TiO₃ Ceramic

Varade,

Pandey,

Sowmya

et al. 2023

ACS Appl. Electron. Mater.

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A temperature-dependent polarization switching study reveals a normal ferroelectric P–E loop to an antiferroelectric double hysteresis loop in the vicinity of depolarization temperature (400 K, T d), which is believed to show a strong electrocaloric effect (ECE) and electrical energy-storage density (W rec) in (Na0.8K0.2)0.5Bi0.5TiO3 (NKBT) ceramic when measured by an indirect method. Structural analysis using X-ray diffraction, Raman spectroscopy, and transmission electron microscopy studies confirmed the coexistence of tetragonal (P4mm) and rhombohedral (R3c) phases. A temperature-dependent dielectric study has revealed a frequency dispersion around 400 K, which hints at the presence of a frustrated interaction resulting in the slowing down of polar domain dynamics below a diffuse phase transition. The high value of ECE in the lead-free NKBT ceramic is also investigated by a direct method, confirming the multifunctional nature of NKBT and its usefulness for applications in refrigeration and energy storage. A direct method of electrocaloric (EC) measurement in NKBT ceramic exhibits an adiabatic temperature change (ΔT) ∼ 1.10 K and an EC strength (ξ) ∼ 0.55 Kmm/kV near T d at an externally applied field of 20 kV/cm, which is consistent with the literature. The recoverable energy (W rec) ∼ 0.78 J/cm3 and electrical storage efficiency (η) ∼ 86% are also observed near T d when an applied field of 20 kV/cm is switched at 1 Hz. This behavior is ascribed to the delicate balance between the field-induced normal ferroelectric–antiferroelectric transition and the thermal energy needed to disrupt the frustrated interaction.

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“…This is because the indirect method only calculates the polarization along the direction of the electric field. The direct method, however, will measure the temperature change caused by the polarization in all directions …”

Section: Resultsmentioning

confidence: 99%

Direct and indirect measurement of large electrocaloric effect in barium strontium titanate ceramics

Dai

Wang

Huang

et al. 2019

Int J Applied Ceramic Tech

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Barium strontium titanate (Ba1‐xSrxTiO3‐BST) ceramics, where x = 0.05, 0.15, 0.25, and 0.35, was prepared via a solid‐state reaction method. The lattice structures and morphologies of the ceramic samples were analyzed using X‐ray diffraction and scanning electron microscopy technologies. The dielectric and ferroelectric properties of the BST ceramics were characterized using a precision impedance analyzer and a ferroelectric polarization‐electric field (P‐E) hysteresis loop tester, respectively. The electrocaloric effect was indirectly calculated using the Maxwell relations and P‐E loops as a function of temperature and electrical field, and also directly measured using a computer‐controlled thermocouple and high‐voltage power supply. An adiabatic temperature change of 1.82 K was procured, indicating a promising potential in the applications as cooling devices.

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Enhanced Electrocaloric Effect in Sr²⁺-Modified Lead-Free BaZr_xTi_1–xO₃ Ceramics

Cited by 44 publications

References 41 publications

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Excellent Electrocaloric and Energy Storage Capabilities in (Na_0.8K_0.2)_0.5Bi_0.5TiO₃ Ceramic

Direct and indirect measurement of large electrocaloric effect in barium strontium titanate ceramics

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Enhanced Electrocaloric Effect in Sr2+-Modified Lead-Free BaZrxTi1–xO3 Ceramics

Cited by 44 publications

References 41 publications

Large Electrocaloric Effect in (Bi0.5Na0.5)TiO3-Based Relaxor Ferroelectrics

Large Electrocaloric Effect in (Bi0.5Na0.5)TiO3-Based Relaxor Ferroelectrics

Excellent Electrocaloric and Energy Storage Capabilities in (Na0.8K0.2)0.5Bi0.5TiO3 Ceramic

Direct and indirect measurement of large electrocaloric effect in barium strontium titanate ceramics

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Product

Resources

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Enhanced Electrocaloric Effect in Sr²⁺-Modified Lead-Free BaZr_xTi_1–xO₃ Ceramics

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Large Electrocaloric Effect in (Bi_0.5Na_0.5)TiO₃-Based Relaxor Ferroelectrics

Excellent Electrocaloric and Energy Storage Capabilities in (Na_0.8K_0.2)_0.5Bi_0.5TiO₃ Ceramic