Phase-transition induced giant negative electrocaloric effect in a lead-free relaxor ferroelectric thin film

Biaolin Peng, Qi Zhang, Bai Gang, Glenn J.T. Leighton, Christopher Shaw, Steven J. Milne, Bingsuo Zou, Wenhong Sun, Haitao Huang, Zhonglin Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

82 Citations (Scopus)


Ferroelectric/antiferroelectric thin/thick films with large positive or negative electrocaloric (EC) effects could be very useful in designing commercial refrigeration devices. Here, a giant negative EC effect (maximum ΔT ∼ -42.5 K with ΔS ∼ -29.3 J K-1 kg-1) comparable to the best positive EC effects reported so far is demonstrated for 0.5(Ba0.8Ca0.2)TiO3-0.5Bi(Mg0.5Ti0.5)O3 (BCT-BMT) lead-free relaxor ferroelectric thin films prepared on Pt(111)/TiOx/SiO2/Si substrates using a sol-gel method. An electric-field induced structural phase transition (nanoscale tetragonal and orthorhombic to rhombohedral) along the out-of-plane [111] direction plays a very key role in developing the giant negative EC effect. This breakthrough will pave the way for practical applications of next-generation refrigeration devices with high cooling efficiency in one cycle by ingeniously utilizing and combining both the giant negative and positive EC effects. Moreover, a large energy density of 51.7 J cm-3 with a high power density of 1.15 × 1010 W kg-1 at room temperature is also achieved in the thin film, indicating that it is also an attractive multifunctional material for energy storage.

Original languageEnglish
Pages (from-to)1708-1717
Number of pages10
JournalEnergy and Environmental Science
Issue number5
Publication statusPublished - 1 May 2019

ASJC Scopus subject areas

  • Environmental Chemistry
  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Pollution


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