Mn/Se,MnO_2/Se和Mn/SeO_2体系形成的团簇离子的质谱研究

A Study of Mn-Se and Mn-O-Se Cluster Ions Using Mass-spectrometry

用飞行时间质谱法研究了激光直接溅射 Ｍｎ／Ｓｅ混合样品产生的二元团簇、团簇的光解行为及溅射ＭｎＯ２／Ｓｅ和 Ｍｎ／ＳｅＯ２样品产生的团簇正负离子．在 Ｍｎ－Ｓｅ二元团簇中，（Ｍｕｓｅ）ｎ＋是正离子的主要组分，［（Ｍｕｓｅ）ｎＳｅ］－是负离子的主要组分．当ｎ<５时，（Ｍｕｓｅ）ｎ＋的紫外光解有多种通道； ｎ≥５时光解以剥落ＭｕＳｅ方式进行．激光直接溅射 ＭｎＯ２／Ｓｅ， Ｍｎ／ＳｅＯ２两种体系产生的正负离子极为相似，符合团簇的气相聚合生长机理．正离子中（Ｍｎｏ）ｎ＋是主要组分，负离子中Ｓｅｎ－，（ＳｅＯ）－和（ＳｅｎＯ３）－是主要组分．

Time-of-flight mass spectrometry was used to study Mn-Se and Mn-O-Se cluster ions produced by laser direct vaporization of solid samples. In Mn-Se binary cluster ions, (MuSe)n+ is the main composition of positive cluster ions, while [(MuSe)nSe]- is the main composition of negative cluster ions. When a mass-selected (MuSe)n+ was photolyzed, the photolysls produt ions have the same general composition (MuSe)m+. In Mn-O-Se ternary system, the main positive cluster ions produced are Mn-O binary clusters, in which [(MnO)n]+ has a high intensity, while the negative cluster ions include Sen-[SenO]-, [SenO3]- and [MnSen]-. It seems that the cluster ions were produced by the vaporization of solid sample and this conforms to a gas-phase aggregation mechanism.