|
|||||
|
|
Room-Temperature Symmetric Giant Positive and Negative Electrocaloric Effect in PbMg0.5W0.5O3 Antiferroelectric Ceramic |
|
| Authors: | Junjie Li Hong-Hui Wu Jianting Li Xiaopo Su Ruowei Yin Shiqiang Qin Dong Guo Yanjing Su Lijie Qiao Turab Lookman Yang Bai |
| Institution: | 1. Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083 China
Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083 China;2. Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083 China School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China;3. Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083 China School of Mechanical and Automotive Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 China;4. School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, 200093 China;5. AiMaterials Research LLC, Santa Fe, NM, 87501 USA;6. Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083 China |
| Abstract: | As an emerging solid-state refrigeration technology with zero-emission and high energy conversion efficiency, there is a compelling need for ferroelectric materials with giant electrocaloric effects (ECEs) at room temperature suitable for refrigeration applications. The complex perovskite antiferroelectric (AFE), PbMg0.5W0.5O3, containing non-equivalent B-site ions with a symmetric giant positive and negative ECE near room temperature is presented. At the Curie temperature of 36 °C, the first-order AFE–paraelectric phase transition gives rise to a large enthalpy change of 3.92 J g?1, more than four times that of BaTiO3. This leads to a significant ECE under the influence of an electric field. The direct electrocaloric characterization shows that the adiabatic temperature change, ΔT, exhibits symmetric peaks with a giant positive maximum of 1.79 K (ΔS = 1.68 J kg?1 K?1) at 36 °C and a negative maximum of ?2.02 K (ΔS = ?1.93 J kg?1 K?1) at 34 °C. The ultrahigh magnitude of ΔT near room temperature makes PbMg0.5W0.5O3 a superior electrocaloric material far beyond traditional PbZrO3-based AFEs. The coexistence of symmetric giant positive and negative ΔT to further improve cooling efficiency is expected. In addition, the good reversibility and negligible leakage current should pave the way for practical applications. |
| Keywords: | antiferroelectric ceramic electrocaloric effect lead magnesium tungstate phase transition solid-state refrigeration |