Nanoscale domain engineering and characterization of ferroelectric domains
Nanoscale domain engineering and characterization of ferroelectric domains
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DOI：
10.1088/0957-4484/10/4/308
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发表时间：
1999-12
期刊：
影响因子：
3.5
通讯作者：
L. Eng
中科院分区：
文献类型：
--
作者：
L. Eng
使用扫描力显微镜（SFM）证明了铁电晶体中的纳米尺度畴工程，其横向畴尺寸小至直径25 nm。SFM的各种模式被用来测量铁电畴中的内部极化场和外部由束缚表面电荷引起的杂散场。从这些测量的铁电畴的有效的三维排列重建。在尖端和反电极之间施加强电场，启动畴切换。新的成核域的大小被发现显着地依赖于开关条件，即所施加的电场强度和开关时间。直径小于100 nm的畴导致电场Eexp >50 kV cm-1，并施加超短时间τexp <30 µs。此外，矫顽场的纳米级的BaTiO 3单晶铁电畴被发现测量1.4千伏cm-1，远远超过散装值。畴转换过程中的瞬态响应分析表明，畴成核在不到100 µs的时间内进行。有了这些工具，我们能够记录纳米级的磁滞回线监测成功的畴反转和一个良好的建立不同的铁电结构之间的材料对比度优于0.1%的分辨率。
Nanoscale domain engineering in ferroelectric crystals is demonstrated down to a lateral domain size of 25 nm in diameter using scanning force microscopy (SFM). The various modes of SFM are used to measure both the internal polarization field and external stray field arising from bound surface charges in ferroelectric domains. From these measurements the effective three-dimensional arrangement of ferroelectric domains is reconstructed. Domain switching is initiated applying strong electric fields between the tip and counter electrode. The size of freshly nucleated domains is found to depend dramatically on the switching conditions, i.e. the applied electric field strength and switching time. Domains of less than 100 nm in diameter result for an electric field Eexp >50 kV cm-1 applied for an ultra-short time period τexp <30 µs. Also, the coercive field of nanoscale ferroelectric domains in BaTiO3 single crystals is found to measure 1.4 kV cm-1, much more than the bulk value. Analysis of the transient response during domain switching shows that domain nucleation proceeds within less than 100 µs. With these tools we are able to record nanoscale hysteresis loops monitoring both the successful domain reversal and a well established material contrast between different ferroelectric structures with a resolution of better than 0.1%.