Wu Jie, Qi He, Yao Yonghao, Chen Liang, Li Wenchao, Liu Hui, Deng Shiqing, Chen Jun
Hainan University, Haikou 570228, Hainan Province, China.
Department of Physical Chemistry, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
ACS Appl Mater Interfaces. 2023 Dec 4. doi: 10.1021/acsami.3c14218.
An outstanding challenge for eco-friendly ferroelectric (FE) refrigeration is to achieve a large adiabatic temperature change within a broad temperature range originating from the electrocaloric (EC) effect, which is expected to be realized in antiferroelectric (AFE) materials owing to the large entropy change during electric field and thermally induced phase transition. In this work, a large EC response over a wide response temperature range can be achieved slightly above room temperature via designing the phase transition of NaNbO. An irreversible to reversible AFE-FE phase transition on heating induced by the introduction of CaZrO into NaNbO plays a key role in the optimized electrocaloric refrigeration. Accordingly, accompanying the local structure transformation corresponding to the B-site ions, the transition temperature between the square polarization-electric field (-) hysteresis loop (the irreversible AFE-FE phase transition induced by the electric field) and the repeatable double - hysteresis loop (the electric field induced reversible AFE-FE phase transition) was tailored to around room temperature, in favor of extending large entropy change to the wide temperature range. This work provides an efficient approach to designing lead-free EC materials with excellent EC performance, promoting the advancement of environmentally friendly solid-state cooling technology.
对于环保型铁电（FE）制冷而言，一个突出的挑战是在源于电热（EC）效应的宽温度范围内实现大的绝热温度变化，由于电场和热诱导相变过程中的大熵变，预计反铁电（AFE）材料可实现这一点。在这项工作中，通过设计NaNbO的相变，可在略高于室温的宽响应温度范围内实现大的EC响应。将CaZrO引入NaNbO所引发的加热过程中不可逆到可逆的AFE-FE相变在优化电热制冷中起关键作用。相应地，伴随着与B位离子对应的局部结构转变，方形极化-电场（-）滞后回线（由电场诱导的不可逆AFE-FE相变）和可重复双滞后回线（电场诱导的可逆AFE-FE相变）之间的转变温度被调整到室温左右，有利于将大熵变扩展到宽温度范围。这项工作为设计具有优异EC性能的无铅EC材料提供了一种有效方法，推动了环境友好型固态冷却技术的进步。
