Au_nP_m~±离子的激光产生及其质谱研究

Laser Generation and Mass Spectrometry of Au_nP_m~±

以高能量密度的脉冲激光束在高真空中直接溅射金粉和红磷的混合物，产生了丰富的金-磷二元原子簇正负离子（m=1～21，n=1～20）和，记录了它们的飞行时间质谱．这些簇离子的相对信号强度大都呈现奇偶交替的变化规律．随着成簇原子数的增加，簇离子组分中磷的相对含量逐渐减少，对应于相同成簇金原子数的成簇磷原子数分布范围变窄，簇离子的结构与性质逐渐由简单络离子向其宏观凝聚态化合物转化．在较大的簇离子中，成簇金原子很可能相互成键。

(m = 1 ~21, n= 1 ~2O) and (n = 1 ~ l5, m = 1 ~ 13 ) were generated by laser ablating the mixture of gold and red phosphorus powders, and their mass spectra were recorded by a time-of-flight mass spectrometer. The mass spectra were analyzed and the mass distributions of the binary cluster ions were studied as a function of the cluster size.The relative signal intensities of most observed cluster ions exhibit even/odd alternation.With increase of the cluster size, increment of clustering phosphorus atoms, m, is much less than that of clustering gold atoms, and the distribution of m for the same m of tends to be narrower. The results suggest that, at least in the larger cluster ions, the clustering gold atoms are bonded together to form the core of the clusters.