铬/磷二元团簇的形成和光解

用532nm的Nd:YAG激光直接溅射铬/磷粉末混合物样品产生铬/磷团簇,并用串级飞行时间质谱仪研究了二元团簇的组份分布及紫外激光光解规律.实验表明,铬/磷极易形成富磷的二元团簇离子,CrP_m⁺团簇离子系列表现出明显的奇偶振荡效应,且CrP₄⁺,Cr_nP₈⁺(n=1～4),Cr₄P₉⁺,Cr₅P₁₁⁺,Cr₆P₁₂⁺和Cr₈P₁₄⁺等为质谱中丰度较大的离子,不随样品组成的变化而变化,光解时主要以失去中性P₂和P₄的方式进行解离,尝试对其电子结构进行推测.并与铬/硫二元团簇的形成和光解结果作简单对比.

Formation and Photodissociation of Chromium/Phosphorus Binary Clusters

Chromium/Phosphorus binary clusters were produced by direct laser ablation and analyzed by tandem time-of-flight mass spectrometer. The main clusters formed were rich in phosphorus. There is an oscillation in CrP+m series(the peaks with even m are stronger than those with odd m, especially the peaks of CrP+4 and CrP+8 are the strongest) and this may be ascribed to the specific stability of P4 structure. There are some strong peaks such as Cr3P+8, Cr4P+9, Cr5P+11, Cr6P+12, Cr8P+14, etc., which dont change with the change of the ratios of Cr to P in the samples, and their stability could be explained with an electron model of valence electrons filling the d orbitals of Cr. The results of photodissociation just accord with the model.