Vibrational Line Broadening Mechanisms for Molecules Adsorbed on Metal Surfaces

金属表面吸附分子的振动线展宽机制

• 批准号: 8907398
• 负责人: Michael Trenary
• 金额: $ 25.67万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-15 至 1993-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8907398&HistoricalAwards=false
• 关键词: Vibrational; Line; Broadening; Mechanisms; Molecules

This project is in the general area of analytical and surface chemistry and in the subfield of surface vibrational spectroscopy. High resolution vibrational spectra of a variety of molecular species adsorbed on metal surfaces will be measured using Fourier transform infrared reflection-absorption spectroscopy (FT-IRAS). The limits of IRAS will be extended: 1) to study adsorbate-substrate vibrations; 2) to characterize the temperature dependence of vibrational line shapes at temperatures as low as 10 K; 3) to characterize the line shapes of overtones; 4) to characterize and analyze the influence of order-disorder phase transitions on adsorbate lineshapes. Chemical systems to be studied include the molecular species phosphorus trifluoride, carbon monoxide and ethylidyne on single-crystal faces of platinum and nickel. The intrinsic lineshapes of vibrational spectra contain information on adsorbate-adsorbate interactions, the extent of vibrational coupling to other modes, and the lower bound of other vibrational modes. The wide range of temperatures that will be employed in this study and the possibility of freezing out phonon mechamisms will permit discrimination among various competing mechanisms of line broadening.

该项目位于分析和表面化学的一般领域以及表面振动光谱的子场。 将使用傅立叶变换红外反射 - 吸收光谱（FT-IRA）测量各种分子物种的高分辨率振动光谱。 IRA的限制将扩大：1）研究吸附物底物振动； 2）表征在低至10 K的温度下振动线形状的温度依赖性； 3）表征泛音的线形； 4）表征和分析订单 - 划分相变对吸附物线形的影响。 要研究的化学系统包括铂和镍的单晶面上的分子种类三氟化磷，一氧化碳和乙基乙烯。 振动光谱的固有线形包含有关吸附物吸附物相互作用的信息，振动耦合到其他模式的程度以及其他振动模式的下限。 这项研究中将采用的广泛温度以及冻结声子机制的可能性将允许在各种竞争线扩展机制之间进行歧视。