Mechanisms of imprint effect on ferroelectric thin films
Mechanisms of imprint effect on ferroelectric thin films
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DOI：
10.1063/1.1984075
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发表时间：
2005-07
影响因子：
3.2
通讯作者：
Yan Zhou;H. Chan;C. Lam;F. G. Shin
中科院分区：
文献类型：
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作者：
Yan Zhou;H. Chan;C. Lam;F. G. Shin
我们发展了一个单层/双层模型来解释铁电薄膜测量的D-E磁滞回线(压痕)的水平移动。这种现象可以通过考虑三种机制或其多重效应来解释：(1)薄膜/电极晶格失配或夹持引起的应力，(2)例如氧空位引起的磁畴钉扎，或(3)薄膜/电极表面层中铁电性能的退化。首先，我们发现在应力影响下的磁滞回线有很大的水平位移，其大小与实验中观察到的相当。其次，假设在均匀的铁电薄膜的膜/电极界面处存在一个具有大矫顽场的伪非切换层，在这种情况下，我们的模拟也显示出大的压痕效应。第三，我们还发现依赖于时间的空间电荷限制传导很可能是印迹发生的原因之一。
We have developed a single/double layer model to explain horizontal shifting of measured D-E hysteresis loops (imprint) for ferroelectric thin films. Such phenomenon can be explained by considering three mechanisms or their multiple effects: (1) stress induced by film/electrode lattice mismatch or clamping, (2) domain pinning induced by, e.g., oxygen vacancies, or (3) degradation of ferroelectric properties in film/electrode surface layers. First, it is found that hysteresis loops under the influence of stress exhibit large horizontal shifts with magnitudes comparable to those observed in experiments. Second, a pseudo-non-switching layer with a large coercive field is assumed to be present at the film/electrode interface in an otherwise homogeneous ferroelectric thin film, and in this case our simulation also shows a large imprint effect. Third, it is also found that time-dependent space-charge-limited conduction is likely to be one origin for the occurrence of imprint.