An experimental set-up for generation and characterization of metal clusters

An experimental facility has been designed, fabricated and installed for th e production and mass characterization of metal clusters. The metal cluster s can be,produced in a flow tube reactor by laser vapourisation of target m etals and characterized by an indigenously designed and fabricated time of flight mass spectrometer (TOFMS). This set-up can be used to carry out a va riety of size-dependent physico-chemical properties of metal clusters in ga s-phase, viz., stability pattern, ionization potential, fragmentation behav iour and chemical reactivity, etc. The performance of the mass spectrometer has been tested by ionizing different organic molecules like aniline, acet one, benzene, diethyl ether, etc., using third harmonic (355nm) of Nd:YAG l aser. The resolution of this TOFMS is similar to 500. Vapourisation of Fe t arget in the flow tube reactor results in the monomer signal of Fe atoms, w hich reduces on addition of ethylene indicating the reaction of ethylene mo lecules with Fe atoms. Nano-sized Fe and Al metal particles have been depos ited on silicon using this machine and characterised by scanning electron m icroscopy.