Large electrocaloric effect under electric field behavior in potassium sodium niobate ceramics with incompletely overlapped phase boundaries†

IF 10.7 2区材料科学 Q1 CHEMISTRY, PHYSICAL

Journal of Materials Chemistry A Pub Date : 2022-02-16 DOI:10.1039/D1TA10899A

Hong Tao, Jie Yin, Chunlin Zhao, Bo Wu, Lin Zhao, Jian Ma and Jiagang Wu

引用次数: 6

Abstract

An enhancement of the electrocaloric effect with incomplete overlap of the FE–FE and FE–PE phase boundaries in KNN-based ceramics.

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不完全相界重叠铌酸钾钠陶瓷在电场行为下的大电热效应

基于电热效应(ECE)的固态制冷技术已成为取代蒸汽压缩制冷的一个有前途的候选技术。环境友好型无铅铁电材料因其铁电性大、相结构丰富而具有ECE的潜力而备受关注。为了在室温下实现宽温度跨度(Tspan)的高ECE，典型的策略是将铁电-准电相边界移至室温，同时不可避免地存在弛豫行为。然而，当居里温度(TC)降低到室温时，铁电性总是严重恶化，从而限制了温度变化(ΔT)。本文首次在铌酸钠钾(KNN)基陶瓷中成功构建了一种基于相位工程的新策略，即基于菱形-四边形(R-T)和四边形-立方(T-C)相边界的不完全重叠相边界来增强ECE。结合电场行为的贡献，揭示了在电场作用下极化能垒降低导致的极化旋转加速和去除电场后的强化逆转，并伴有强铁电性。随后，获得了强增强的ECE，即ΔT =1.14 K at 100 kV cm?1和70°C以及34°C的宽Tspan，展示了改进的综合ECE，符合电气设备冷却系统的要求。同时，随着与温度相关的临界电场(ECE)的存在，ECE系数(ΔT/ΔE)的电场依赖性呈现出异常趋势。这项工作提出了一种环保的ECE材料，具有高性能的固态冷却应用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Materials Chemistry A CHEMISTRY, PHYSICAL-ENERGY & FUELS

CiteScore

19.50

自引率

5.00%

发文量

1892

审稿时长

1.5 months

期刊介绍： The Journal of Materials Chemistry A, B & C covers a wide range of high-quality studies in the field of materials chemistry, with each section focusing on specific applications of the materials studied. Journal of Materials Chemistry A emphasizes applications in energy and sustainability, including topics such as artificial photosynthesis, batteries, and fuel cells. Journal of Materials Chemistry B focuses on applications in biology and medicine, while Journal of Materials Chemistry C covers applications in optical, magnetic, and electronic devices. Example topic areas within the scope of Journal of Materials Chemistry A include catalysis, green/sustainable materials, sensors, and water treatment, among others.