Large nonlinear dielectric properties of artificial BaTiO3/SrTiO3 superlattices
Large nonlinear dielectric properties of artificial BaTiO3/SrTiO3 superlattices
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DOI：
10.1063/1.1477934
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发表时间：
2002-05
影响因子：
4
通讯作者：
Juho Kim;Youngnam Kim;Young-sung Kim;Jaichan Lee;L. Kim;D. Jung
中科院分区：
文献类型：
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作者：
Juho Kim;Youngnam Kim;Young-sung Kim;Jaichan Lee;L. Kim;D. Jung
在MgO（100）衬底上制备了BaTiO_3（BTO）/SrTiO_3（STO）人工超晶格。超晶格中BTO/STO层的周期性从一个晶胞到125个晶胞厚度变化。介电常数和它的非线性（或电压可调谐性）表现出类似的行为，作为周期性的变化。在临界厚度范围内，随着BTO/STO堆叠周期的减小，超晶格的电压可调谐性增加。类似地，晶格畸变，即，BTO层和STO层的晶格参数沿着表面法向与平行方向的比值随着周期性的减小而增大。实现了电压可调谐性的显著增强。超晶格表现出大的电压可调性（94%，迄今为止的最高值）的周期性的BTO 2-晶胞/STO 2-晶胞在每层的最大晶格畸变。这表明超晶格的非线性介电性质与晶格的介电常数密切相关。
BaTiO3(BTO)/SrTiO3(STO) artificial superlattices have been made on MgO (100) substrates. The periodicity of the BTO/STO layers in the superlattice was varied from one-unit cell to 125-unit cell thickness. The dielectric constant and its nonlinearity (or voltage tunability) showed similar behavior as the periodicity was varied. The voltage tunability of the superlattice increased with decreasing stacking periodicity of the BTO/STO within the critical thickness. Similarly, the lattice distortion, i.e., the ratio of the lattice parameter along surface normal to parallel, of the BTO and STO layers increased with decreasing the periodicity. Remarkable enhancement of the voltage tunability has been achieved. The superlattice exhibited large voltage tunability (94%, the highest value to date) at the periodicity of BTO2-unit cell/STO2-unit cell at which the maximum lattice distortion of each layer was obtained. This suggests that the nonlinear dielectric property of the superlattice is closely related with the la...