Large Room Temperature Negative Electrocaloric Effect in Novel Antiferroelectric PbHfO 3 Films

• Published in: ACS applied materials & interfaces Vol. 13; no. 18; pp. 21331 - 21337
• Main Authors: Huang, Xian-Xiong, Zhang, Tian-Fu, Gao, Rong-Zhen, Huang, Hou-Bing, Ge, Peng-Zu, Tang, Hui, Tang, Xin-Gui
• Format: Journal Article
• Language: English
• Published: United States 12.05.2021
• Subjects: antiferroelectric; Landau theory; electrocaloric effect; PbHfO3; solid-state refrigeration
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.1c03079

Extremely high temperature in a chip will severely affect the normal operation of electronic equipment; however, the traditional air conditioning cooling technology is unsuitable for integrated circuit cooling. It is necessary to develop convenient and high-efficiency cooling techniques. In this paper, PbHfO antiferroelectric (PHO AFE) film was fabricated by a sol-gel method and was first found to be a promising electrocaloric (EC) material with high temperature change (Δ ∼ -7.7 K) and acceptable EC strength (|Δ /Δ | ∼ 0.023 K cm kV ) at room temperature. In addition to the negative EC effect (ECE), a large positive ECE can be observed at high temperature. The outstanding ECEs and their combination will make the PHO film one of the potential candidates for next-generation solid-state refrigeration. To understand the underlying physical mechanism for positive and negative ECEs in the PHO AFE film, a modified Ginzburg-Landau-Devonshire free-energy theory is adopted.