Structure, Stability and Electron Counting Rules in Transition Metal Encapsulated Silicon and Germanium Clusters

摘要: Transition metal (TM) doped silicon and germanium clusters have been studied widely over the last two-three of decades. The initial motivation was to understand metal-semiconductor interfaces, couple magnetism in TM atoms with semiconducting properties silicon. However, later on, focus shifted production stable, encapsulated or cage clusters, possibly having magnetic moment. most fundamental question experiments threw up is, what are stable these series? And, how their stability? Like other branches physics chemistry, simple electron counting rules, such as 18-electron rule inorganic organometallic idea shell filling a spherical gas, were invoked explain stability some clusters. different found be under experimental conditions, making it somewhat unclear whose one has explain. Faced challenges, large number theoretical studies devoted elucidating issues. Quite early authors (Sen Mitas, e.g.) argued that rules may not all observations TM–Silicon though can ostensibly explained by rules. recent works from Bandyopadhyaya Sen, Khanna co-workers show only limited applicability A detail review literature discussing issues is presented, still open questions pointed out.