【摘要】 低维纳米材料具有异常的红外性能,其本质与纳米材料的尺度、结构、与外场的相互作用等密切相关.本文利用电偶极子间相互作用近似计算了多粒子体系纳米粒子间的局域电场,表征了球形纳米粒子表面及附近局域电场随粒子半径R的变化,以及CO分子吸附于球形纳米粒子表面时的受力及分布情况.结果在一定程度上诠释了低维纳米材料异常红外性能的本质.更多还原

【Abstract】 Low dimensional nanomaterials exhibit generally anomalous infrared properties,which include the surface enhanced infrared absorption(SEIRA),the Fano-like infrared effects(FLIREs) and the abnormal infrared effects(AIREs).Previous experimental studies demonstrated that the anomalous infrared properties depend strongly on the size and structure of nanomaterials,as well as on the interaction of nanomaterials with radiation of electromagnetic field.The current study has put emphasis upon the local electric filed,which has an significant impact on the features of infrared absorption of adsorbates,of nanostructured systems containing a large number of nanoparticles.By taking into account of the interaction between dipoles,the Local electric field near nanoparticles has been calculated.Changes of the electric field along with variation of nanoparticle radius was illustrated.Distribution of CO adsorbates on nanoparticles was discussed as results of interaction between adsorbed CO molecules and that of interaction between adsorbates and nanoparticles.It has demonstrated that the force of electric filed,which is proportional to E/θ and is imposed on adsorbed CO molecules,varied on the surface of nanoparticles.The maximal value of E/θ appears in equator of spherical nanoparticles,and the minimal value of E/θ is located on both poles of the spherical nanoparticles.The results have thrown light in illuminating the origin of anomalous IR properties of nanomaterials.更多还原