Relaxor ferroelectrics and intrinsic inhomogeneity
Relaxor ferroelectrics and intrinsic inhomogeneity
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DOI：
10.1209/epl/i2005-10076-4
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发表时间：
2005-07-01
期刊：
影响因子：
--
通讯作者：
Egami, T
中科院分区：
文献类型：
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作者：
Bussmann-Holder, A;Bishop, AR;Egami, T
弛豫铁电体（RF）的特点是漫射铁电跃迁和高和频率相关的介电磁化率。非rf仅在转变温度附近表现出高介电响应，而rf在很大的温度范围内表现出高响应。尽管其历史悠久，但由于其结构的复杂性，其微观起源仍然未知。RF行为仅在非化学计量的混合离子系统中观察到，并且代表了介电软基质和高极化掺杂离子的复合物。在这里，我们提出了一个具有内在非均匀性的多分量场景，这表明空间局部激励（离散呼吸）耦合到软矩阵产生自一致的多长度尺度响应，并成功地解释了弛豫铁电行为。
Relaxor ferroelectrics (RF) are characterized by diffuse ferroelectric transitions and high and frequency-dependent dielectric susceptibilities. Non-RFs show high dielectric responses only in the direct vicinity of the transition temperature whereas RFs exhibit high responses over a large temperature range. Despite their long history, the microscopic origin of RFs is still unknown due to their structural complexity. RF behaviour is exclusively observed in nonstoichiometric, mixed ion systems, and represents a composite of dielectrically soft matrix and highly polarizable doped ions. Here we propose a multi-component scenario with intrinsic inhomogeneity, which shows that spatially localized excitations (discrete breathers) coupled to the soft matrix yield a self-consistent multi-length scale response and successfully explains the relaxor ferroelectric behaviour.