Aging behavior in single-domain Mn-doped BaTiO 3 crystals: Implication for a unified microscopic explanation of ferroelectric aging
Aging behavior in single-domain Mn-doped BaTiO 3 crystals: Implication for a unified microscopic explanation of ferroelectric aging
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DOI：
10.1103/physrevb.73.094121
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发表时间：
2006-03
影响因子：
3.7
通讯作者：
Lixue Zhang;X. Ren
中科院分区：
文献类型：
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作者：
Lixue Zhang;X. Ren
铁电材料的铁电、介电和压电性能随时间的变化，即铁电老化现象，在大多数铁电材料中已经观察到。从现象学上讲，老化可以归因于铁电畴的缺陷逐渐稳定，但畴稳定的微观起源仍然存在争议。目前还不清楚畴稳定化是畴壁钉扎引起的边界效应还是整个畴的体积效应。本文制备了单畴无畴壁的掺锰BaTiO_3单晶，研究了其磁滞回线的老化行为。我们发现，老化后，单畴样品的矫顽场显着增加，清楚地表明单畴的强稳定性。此外，样品表现出异常的双磁滞回线，这对应于一个有趣的可逆域切换过程。这些都是老化使单畴稳定的直接证据。我们的研究结果排除了畴壁钉扎效应的解释，并强烈表明，体积效应是滞后回线老化的主导机制。我们进一步表明，体积效应的微观起源自然来自于一般的点缺陷的一致性。这种微观机制不仅可以解释电滞回线大信号老化，而且可以解释介电常数和压电常数小信号老化，从而为各种铁电老化提供了统一的微观解释。
The change of ferroelectric, dielectric, and piezoelectric properties with time, the ferroelectric aging phenomena, has been observed in most ferroelectrics. Phenomenologically, aging can be attributed to the gradual stabilization of ferroelectric domains by defects, but the microscopic origin of the domain stabilization has remained controversial. It is unclear whether the domain stabilization is a boundary effect caused by domainwall-pinning or a volume effect stabilization of the whole domain. In the present paper, we made a singledomain domain-wall-free Mn-doped BaTiO3 single crystal and studied the aging behavior of its hysteresis loop. We found that after aging, the single-domain sample shows a significant increase in the coercive field, clearly indicating a strong stabilization of the single domain. Furthermore, the sample exhibits an abnormal double hysteresis loop, which corresponds to an interesting reversible domain switching process. These are direct evidence for the stabilization of single domain by aging. Our results preclude any explanation by the domain-wall-pinning effect and strongly suggest that the volume effect is the governing mechanism for the aging in hysteresis loop. We further show that the microscopic origin of the volume effect comes naturally from a general symmetry-conforming property of point defects. Such a microscopic mechanism can explain not only the aging in hysteresis loop large signal aging but also the aging in dielectric and piezoelectric constants small signal aging, thus providing a unified microscopic explanation for all kinds of ferroelectric aging.