声子
反铁电性
电热效应
凝聚态物理
制冷
材料科学
熵(时间箭头)
偶极子
电场
铁电性
物理
电介质
热力学
光电子学
量子力学
作者
Chenhan Liu,Yangyang Si,Menglong Hao,Yi Tao,Shiqing Deng,Ping Lu,Chuanwen Zhao,Zuhuang Chen,Gang Zhang,Yunfei Chen
出处
期刊:Applied physics reviews
[American Institute of Physics]
日期:2023-08-15
卷期号:10 (3)
被引量:1
摘要
Electrocaloric cooling, with the advantages of zero global warming potential, high efficiency, smart size, etc., is regarded as a promising next-generation technology for green refrigeration. The exotic negative electrocaloric effect (ECE) in antiferroelectric materials forms the basis to improve the caloric cooling power density, but the underlying mechanism remains elusive. By using a fully first-principles method, we successfully simulate the electric field-triggered structural phase transition from antiferroelectric to ferroelectric in a prototypical antiferroelectric material PbZrO3 (PZO). Through tracking the phonon entropy evolution and measuring the temperature-dependent polarization along the transition path, we disclose that the negative ECE in PZO originates from the latent heat associated with phonon entropy rather than the previously recognized dipolar entropy. Accordingly, a new concept of phonon entropy engineering is proposed that engineering the density of states especially for low-frequency phonons can modulate the phonon entropy, which provides an effective route to enhance the cooling power density.
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