Fulvio D, Sivaraman B, Baratta G A, Palumbo M E, Mason N J
Department of Physics & Astronomy, Catania University, Via S. Sofia 64, I-95123 Catania, Italy.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Jun;72(5):1007-13. doi: 10.1016/j.saa.2008.12.030. Epub 2008 Dec 25.
We present novel measurements of the refractive index, density and integrated band strengths of mid-infrared features of solid N(2)O at 16K and of NO(2) and N(2)O(4) in two frozen NO(2):N(2)O(4) mixtures deposited at 16 and 60K. The refractive index and density measurements were performed also for frozen O(2) deposited at 16K. In this case, the integrated band strength values could not be determined since O(2) is a homonuclear molecule and therefore its fundamental mode is not infrared active. The solid samples were analysed by infrared spectroscopy in the 8000/800cm(-1) range. The sample thickness was measured by the interference curve obtained using a He-Ne laser operating at 543nm. The refractive index at this laser wavelength was obtained, by numerical methods, from the measured amplitude of the interference curve. The density values were obtained using the Lorentz-Lorenz relation. Integrated band strength values were then obtained by a linear fit of the integrated band intensities plotted versus column density values. The astrophysical relevance of these novel measurements is briefly discussed.
我们展示了在16K下固态N₂O以及在16K和60K沉积的两种冷冻NO₂:N₂O₄混合物中NO₂和N₂O₄的中红外特征的折射率、密度和积分带强度的新测量结果。还对在16K沉积的冷冻O₂进行了折射率和密度测量。在这种情况下，由于O₂是同核分子，其基模不是红外活性的，因此无法确定积分带强度值。通过在8000/800cm⁻¹范围内的红外光谱对固体样品进行分析。使用工作在543nm的氦氖激光获得的干涉曲线测量样品厚度。通过数值方法从测量的干涉曲线振幅获得该激光波长下的折射率。使用洛伦兹 - 洛伦茨关系获得密度值。然后通过将积分带强度与柱密度值绘制的线性拟合获得积分带强度值。简要讨论了这些新测量结果的天体物理学相关性。
