Giant room temperature elastocaloric effect in metal-free thinfilm perovskites  

作　　者：Cheng Li Yu Hui Huang Jian-Jun Wang Bo Wang Yong Jun Wu He Tian Long-Qing Chen Zijian Hong 

机构地区：[1]Laboratory of Dielectric Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou,China [2]Department of Materials Science and Engineering,The Pennsylvania State University,University Park,PA,USA [3]Cyrus Tang Center for Sensor Materials and Applications,State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou,China [4]Center of Electron Microscopy,State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou,China

出　　处：《npj Computational Materials》2021年第1期1194-1201,共8页计算材料学（英文）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.51572237 and 51802280);the Fundamental Research Funds for the Central Universities(Nos.2020QNA4005,2020FZZX002-01,2020FZZX003-04,and 2021FZZX003-02-03);the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(U1909212);the National Key R&D Program of China(Nos.2018YFC0114902);Z.H.would like to acknowledge a startup grant from Zhejiang University.J.-J.W.and L.-Q.C.gratefully acknowledge the partial support from the Donald W.Hamer Foundation for the Hamer Professorship at Penn State.

摘　　要：Solid-state refrigeration which is environmentally benign has attracted considerable attention.Mechanocaloric(mC)materials,in which the phase transitions can be induced by mechanical stresses,represent one of the most promising types of solid-state caloric materials.Herein,we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric(eC)strengths for the(111)-oriented metal-free perovskite ferroelectric[MDABCO](NH_(4))I_(3)thin-films.The predicted room temperature isothermal eC ΔS_(eC)/Δσ(eC entropy change under unit stress change)and adiabatic eCΔTeC/Δσ(eC temperature change under unit stress change)for[MDABCO](NH_(4))I_(3) are−60.0 J K^(−1)kg^(−1)GPa^(−1) and 17.9 K GPa^(−1),respectively,which are 20 times higher than the traditional ferroelectric oxides such as BaTiO_(3) thin films.We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient(which could be realized through chemical doping,etc.).We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

关 键 词：FERROELECTRIC PEROVSKITE free 

分 类 号：TB33[一般工业技术—材料科学与工程]