Browsing by Author "Milne, Steven J."

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    Compaction of lead zirconate titanate sol-gel coatings
    (Elsevier Science B.V., Amsterdam., 2006-06-01T00:00:00Z) Khan, Mikael A.; Kurchania, Rajnish; Corkovic, Silvana; Zhang, Qi; Milne, Steven J.
    A novel method for the densification of sol-gel films is presented. After elimination of organic decomposition products by heat-treatment at 350 °C and 450 °C, the films are isopressed prior to crystallisation at 550 °C. Consequently, porous lead zirconate titanate films, ~0.7 m in thickness with pore sizes of ~0.1 m could be transformed into dense 0.2 m fil
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    Phase-transition induced giant negative electrocaloric effect in a lead-free relaxor ferroelectric thin film
    (Royal Society of Chemistry, 2019-05-02) Peng, Biaolin; Zhang, Qi; Gang, Bai; Leighton, Glenn J. T.; Shaw, Christopher; Milne, Steven J.; Zou, Bingsuo; Sun, Wenhong; Huang, Haitao; Wang, Zhonglin
    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.