Cao Lina, Sendur Kursat
Faculty of Engineering and Natural Science, Sabanci University, 34956 Istanbul, Turkey.
Materials (Basel). 2019 Sep 22;12(19):3090. doi: 10.3390/ma12193090.
Random surface roughness and surface distortions occur inevitably because of various material processing and fabrication techniques. Tailoring and smoothing the surface roughness can be especially challenging for thermomechanically stable materials, including refractory metals, such as tungsten (W), and polar dielectrics, such as silicon carbide (SiC). The spectral reflectivity and emissivity of surfaces are significantly impacted by surface roughness effects. In this paper, we numerically investigated the surface roughness effects on the spectral reflectivity and emissivity of thermomechanically stable materials. Based on our results, we determined that surface roughness effects are strongly impacted by the correlation length of the Gaussian surface. In addition, our results indicate that surface roughness effects are stronger for the materials at the epsilon-near-zero region. Surface roughness effects are stronger between the visible and infrared spectral region for W and around the wavelength of 12 μ m for SiC, where plasma frequency and polar resonance frequency are located.
由于各种材料加工和制造技术，随机表面粗糙度和表面畸变不可避免地会出现。对于热机械稳定材料，包括难熔金属（如钨（W））和极性电介质（如碳化硅（SiC）），调整和平滑表面粗糙度可能尤其具有挑战性。表面粗糙度效应会显著影响表面的光谱反射率和发射率。在本文中，我们通过数值方法研究了表面粗糙度对热机械稳定材料光谱反射率和发射率的影响。基于我们的结果，我们确定表面粗糙度效应受到高斯表面相关长度的强烈影响。此外，我们的结果表明，在ε近零区域的材料中，表面粗糙度效应更强。对于W，在可见光和红外光谱区域之间，以及对于SiC，在等离子体频率和极性共振频率所在的12μm波长附近，表面粗糙度效应更强。
