论文标题
YB取代的III-V氮化合金中的机电耦合
Electromechanical coupling in Yb-substituted III-V nitride alloys
论文作者
论文摘要
III组氮化合金当前在各种微波通信应用中使用，因为与诸如YBN或SCN等岩石质氮化物合金之后，机电耦合的巨大增强。本文中，通过理论计算和实验研究了YB实体诱导的Wurtzite III-V氮化物中机电耦合的增强。替代引起的机械软化和局部应变可以增强机电耦合。由YB替代引起的机械软化显示对母体ALN或GAN的依赖性较小，这是由YB-YB对在C轴方向上的相互作用引起的，而基于GAN-和ALN合金之间的机电耦合的差异主要来自它们的YB替代品对PiezoElectric响应的增强效应。在基于GAN的合金中观察到了压电反应相对于母氮化物的最大变化，这主要是由于父GAN的小压电常数而被认为。我们的计算还表明，与宿主阳离子更接近离子大小的替代元件更容易替代氮化物，并产生更大的内部应变，以部分促进压电反应的增强。这可以作为一个简单的指南，以识别搜索机电耦合大量增加的合金组件。
Group-III nitride alloys are currently used in various microwave communication applications because of the giant enhancement in electromechanical coupling after alloying with rocksalt nitrides such as YbN or ScN. Herein, the Yb-substitution induced enhancement for electromechanical coupling in wurtzite III-V nitrides is studied via theoretical calculations and experiments. The substitution induced mechanical softening and local strain can enhance electromechanical coupling. The mechanical softening induced by Yb substitution shows less dependence on the parent AlN or GaN, which is caused by the Yb-Yb pair interaction in the c-axis direction, and the difference of electromechanical coupling between the GaN- and AlN-based alloys mainly comes from their enhancement effect of Yb substitution for piezoelectric response. The largest change in piezoelectric response relative to the parent nitride is observed in GaN-based alloy, which is mainly considered as a consequence of small piezoelectric constant of the parent GaN. Our calculations also reveal that the substitutional element with a closer ionic size to the host cation is easier to substitute into the host nitride, and produces a larger internal strain to partly contribute to the enhancement in piezoelectric response. This can serve as a simple guideline to identify alloying components in a search for a massive increase in electromechanical coupling.
