论文标题
使用Picsecond Ultrasonics研究的三层共振的介电纳米薄膜的弹性常数
Elastic constant of dielectric nano-thin films using three-layer resonance studied by picosecond ultrasonics
论文作者
论文摘要
NM级薄膜的弹性常数和声速对于设计声过滤器至关重要。但是，对于介电薄膜，很难测量它们。在这项研究中，我们使用三层结构，其中将介电纳米薄膜夹在较厚的金属膜之间，以测量介电膜的纵向弹性常数。我们提出一个效率函数，以估计组件的最佳厚度。我们使用pt/nio/pt三层膜来确认我们提出的方法。在室温下沉积的NIO的确定的弹性常数小于$ \ sim $ 40 $ \％$。但是，随着沉积温度升高，它接近散装值。我们还揭示了PT膜的弹性常数的不确定性无关紧要，会影响NIO在该结构中确定的弹性常数的准确性。
Elastic constants and sound velocities of nm-order thin films are essential for designing acoustic filters. However, it is difficult to measure them for dielectric thin films. In this study, we use a three-layer structure where a dielectric nano-thin film is sandwiched between thicker metallic films to measure the longitudinal elastic constant of the dielectric film. We propose an efficiency function to estimate the optimal thicknesses of the components. We use Pt/NiO/Pt three-layer films for confirming our proposed method. The determined elastic constant of NiO deposited at room temperature is smaller than the bulk value by $\sim$40$\%$. However, it approaches the bulk value as the deposition temperature increases. We also reveal that uncertainty of the elastic constant of the Pt film insignificantly affects the accuracy of the determined elastic constant of NiO in this structure.
