ACAD SINICA,INST CHEM,BEIJING 100080,PEOPLES R CHINA
; ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100080,PEOPLES R CHINA
The formation and stability of FexPy+ cluster ion produced by laser ablation were investigated. The gas-phase reaction equation in the formation of these cluster ions is P-x+Fe-x(+)-->FexPy+Px-y. And the odd-even variation related to the number of P atom in mass spectrum was explained with the calculation of the electronic occupied state in the cluster ions in which the electronic structure of transition metal dominates the bonding in cluster ions, and the higher ionization energy of even cluster ions results in removing easily electrons from the-single electron occupied states of cluster ions.