Giant polarization in super-tetragonal ferroelectric thin films through interphase strain
Abstract
Strain engineering has emerged as a powerful tool to enhance the performance of known functional materials. Here we demonstrate a general and practical method to obtain super-tetragonality and giant polarization using interphase strain. We use this method to create an out-of-plane–to–in-plane lattice parameter ratio of 1.238 in epitaxial composite thin films of tetragonal lead titanate (PbTiO3), compared to 1.065 in bulk. These thin films with super-tetragonal structure possess a giant remanent polarization, 236.3 microcoulombs per square centimeter, which is almost twice the value of known ferroelectrics. The super-tetragonal phase is stable up to 725°C, compared to the bulk transition temperature of 490°C. The interphase-strain approach could enhance the physical properties of other functional materials.
Citation
Zhang , L , Chen , J , Fan , L , Diéguez , O , Cao , J , Pan , Z , Wang , Y , Wang , J , Kim , M , Deng , S , Wang , J , Wang , H , Deng , J , Yu , R , Scott , J F & Xing , X 2018 , ' Giant polarization in super-tetragonal ferroelectric thin films through interphase strain ' , Science , vol. 361 , no. 6401 , pp. 494-497 . https://doi.org/10.1126/science.aan2433
Publication
Science
Status
Peer reviewed
ISSN
0036-8075Type
Journal article
Collections
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