Ferroic glasses (铁素玻璃))
Yuanchao Ji,Dong Wang, Yu Wang, Yumei Zhou, Dezhen Xue, Kazuhiro Otsuka, Yunzhi Wang &Xiaobing Ren
npj Computational Materials 3:43 (2017)
doi:10.1038/s41524-017-0039-6
Published online:12 October 2017
Abstract| Full Text | PDF OPEN
摘要:铁素玻璃(为应变玻璃、弛豫器和簇自旋玻璃的新总称)是处于冷冻无序状态的铁素体系,是长程有序铁素态的共轭态——铁素体。铁素玻璃显示出铁素体中所没有的一些非凡性质,如,在宽泛温度范围内出现的细电滞回线和性能渐进变化。除了铁素玻璃和铁素体之外,还存在第三种铁素态,即玻璃-铁素体(铁素玻璃和铁素体的复合物),由铁素玻璃的结晶转变而制造,拥有铁素玻璃和铁素体均没有的优越性能。温度-缺陷-浓度通用相图显示,这三类铁素材料(铁素体、铁素玻璃和玻璃-铁素体)对应于三种转变(分别为铁素相变、铁素玻璃转变和铁素玻璃结晶转变)。此外,通过构建相位场模型可再现三个转变的微结构演化和相图,揭示了点缺陷在形成铁素玻璃和玻璃-铁素体中的重要作用。这种相图可用来设计有非凡特性的各种铁素玻璃和玻璃-铁素体。
Abstract: Ferroic glasses (strain glass, relaxor and cluster spin glass) refer to frozen disordered states in ferroic systems; they are conjugate states to the long-range ordered ferroic states—the ferroic crystals. Ferroic glasses exhibit unusual properties that are absent in ferroic crystals, such as slim hysteresis and gradual property changes over a wide temperature range.In addition to ferroic glasses and ferroic crystals, a third ferroic state, a glass-ferroic (i.e., a composite of ferroic glass and ferroic crystal), can be produced by the crystallization transition of ferroic glasses.It can have a superior property not possessed by its two components.These three classes of ferroic materials (ferroic crystal, ferroic glass and glass-ferroic) correspond to three transitions (ferroic phase transition, ferroic glass transition and crystallization transition of ferroic glass, respectively), as demonstrated in a generic temperature vs. defect-concentration phase diagram.Moreover, through constructing a phase field model, the microstructure evolution of three transitions and the phase diagram can be reproduced, which reveals the important role of point defects in the formation of ferroic glass and glass-ferroic.The phase diagram can be used to design various ferroic glasses and glass-ferroics that may exhibit unusual properties.