Polarization switching dynamics governed by the thermodynamic nucleation process in ultrathin ferroelectric films
Polarization switching dynamics governed by the thermodynamic nucleation process in ultrathin ferroelectric films
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DOI：
10.1103/physrevlett.97.247602
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发表时间：
2006-12-15
影响因子：
8.6
通讯作者：
Noh, T. W.
中科院分区：
文献类型：
--
作者：
Jo, J. Y.;Kim, D. J.;Noh, T. W.
在大多数铁电体中，畴成核势垒（U-*）在热上是不可克服的；这被称为“兰道尔悖论”。然而，我们发现，在超薄膜中，大的退极化场可以将U-*降低到与热能（k(B)T）相当的水平，从而导致极化的幂律衰减。我们通过经验发现幂律衰减指数与U-*/k(B)T之间存在普遍关系。这种关系将为电容型铁电器件提供一个实用但基本的极限，类似于磁存储器件的超顺磁极限。
In most ferroelectrics, the domain nucleation barrier (U-*) is thermally insurmountable; this is called "Landauer's paradox." However, we showed that, in ultrathin films, the large depolarization fields could lower U-* to a level comparable to thermal energy (k(B)T), resulting in power-law decay of polarization. We empirically found a universal relation between the power-law decay exponent and U-*/k(B)T. This relation will provide a practical but fundamental limit for capacitor-type ferroelectric devices, analogous to the superparamagnetic limit for magnetic memory devices.