表面效应对zno纳米材料压电性质效应的影响 [外文翻译].zip
表面效应对zno纳米材料压电性质效应的影响 [外文翻译],材料科学与工程 材料物理与化学，外文文献翻译及原文surface effects on the piezoelectricity of zno nanowires表面效应对zno纳米材料压电性质效应的影响a b s t r a c twe utilize classical molecular dynamics to ...
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材料科学与工程 材料物理与化学，外文文献翻译及原文
Surface effects on the piezoelectricity of ZnO nanowires
表面效应对ZnO纳米材料压电性质效应的影响
a b s t r a c t
We utilize classical molecular dynamics to study surface effects on the piezoelectricproperties of ZnO nanowires as calculated under uniaxial loading. An important point toour work is that we have utilized two types of surface treatments, those of chargecompensation and surface passivation, to eliminate the polarization divergence thatotherwise occurs due to the polar (0001) surfaces of ZnO. In doing so, we find that ifappropriate surface treatments are utilized, the elastic modulus and the piezoelectricproperties for ZnO nanowires having a variety of axial and surface orientations are allreduced as compared to the bulk value as a result of polarization reduction in the polar[0001] direction. The reduction in effective piezoelectric constant is found to beindependent of the expansion or contraction of the polar (0001) surface in responseto surface stresses. Instead, the surface polarization and thus effective piezoelectricconstant is substantially reduced due to a reduction in the bond length of the Zn–Odimer closest to the polar (0001) surface. Furthermore, depending on the nanowireaxial orientation, we find in the absence of surface treatment that the piezoelectricproperties of ZnO are either effectively lost due to unphysical transformations from thewurtzite to non-piezoelectric d-BCT phases, or also become smaller with decreasingnanowire size. The overall implication of this study is that if enhancement of thepiezoelectric properties of ZnO is desired, then continued miniaturization of square ornearly square cross-section ZnO wires to the nanometer scale is not likely to achievethis result.
摘要：单轴晶体的计算中，我们使用经典分子动力学理论去研究表面效应对ZnO纳米材料压电效应的影响。我们工作的一个重点是我们使用两种表面处理方式，这些处理方式为了排除ZnO极性面（0001）导致的极化分歧，改变了补偿和表面钝化。做了这些处理后，我们发现如果利用适当的表面处理，ZnO的的弹性模量和压电性质有各种的轴向，并且相对于大多数由于（0001）极化面的极化削减表面极化都进一步减少了。有效压电常数的减少被发现是基于极化面（0001）表面响应膨胀或收缩带来的表面压力。相反，表面极化和有效压电常数大幅度减少是由于Zn–O二聚体的键长接近极性面（0001）表面。再者，根据纳米线轴向的极化，我们发现经过表面处理后ZnO的压电效应由于从纤维锌矿相转变非压电d-BDT相的非物质转变明显的损失，并且也随着纳米线大小的增长而减小。这个研究整体的意义就在于如果增强ZnO对压电性能的要求，然后再继续小型化的平方或近方形截面的ZnO纳米线是不可能获得这个结果的。
Surface effects on the piezoelectricity of ZnO nanowires
表面效应对ZnO纳米材料压电性质效应的影响
a b s t r a c t
We utilize classical molecular dynamics to study surface effects on the piezoelectricproperties of ZnO nanowires as calculated under uniaxial loading. An important point toour work is that we have utilized two types of surface treatments, those of chargecompensation and surface passivation, to eliminate the polarization divergence thatotherwise occurs due to the polar (0001) surfaces of ZnO. In doing so, we find that ifappropriate surface treatments are utilized, the elastic modulus and the piezoelectricproperties for ZnO nanowires having a variety of axial and surface orientations are allreduced as compared to the bulk value as a result of polarization reduction in the polar[0001] direction. The reduction in effective piezoelectric constant is found to beindependent of the expansion or contraction of the polar (0001) surface in responseto surface stresses. Instead, the surface polarization and thus effective piezoelectricconstant is substantially reduced due to a reduction in the bond length of the Zn–Odimer closest to the polar (0001) surface. Furthermore, depending on the nanowireaxial orientation, we find in the absence of surface treatment that the piezoelectricproperties of ZnO are either effectively lost due to unphysical transformations from thewurtzite to non-piezoelectric d-BCT phases, or also become smaller with decreasingnanowire size. The overall implication of this study is that if enhancement of thepiezoelectric properties of ZnO is desired, then continued miniaturization of square ornearly square cross-section ZnO wires to the nanometer scale is not likely to achievethis result.
摘要：单轴晶体的计算中，我们使用经典分子动力学理论去研究表面效应对ZnO纳米材料压电效应的影响。我们工作的一个重点是我们使用两种表面处理方式，这些处理方式为了排除ZnO极性面（0001）导致的极化分歧，改变了补偿和表面钝化。做了这些处理后，我们发现如果利用适当的表面处理，ZnO的的弹性模量和压电性质有各种的轴向，并且相对于大多数由于（0001）极化面的极化削减表面极化都进一步减少了。有效压电常数的减少被发现是基于极化面（0001）表面响应膨胀或收缩带来的表面压力。相反，表面极化和有效压电常数大幅度减少是由于Zn–O二聚体的键长接近极性面（0001）表面。再者，根据纳米线轴向的极化，我们发现经过表面处理后ZnO的压电效应由于从纤维锌矿相转变非压电d-BDT相的非物质转变明显的损失，并且也随着纳米线大小的增长而减小。这个研究整体的意义就在于如果增强ZnO对压电性能的要求，然后再继续小型化的平方或近方形截面的ZnO纳米线是不可能获得这个结果的。
