Formation of Solvated Magnesium Oxide Clusters in Direct Laser Vaporization

The cluster ions produced by the direct laster vaporization of Mg（OH）₂·4MgCO₃·5H₂O are detected by time of flight mass spectrometer.It is found that there appear in situ solvation reactions of magnesium oxide clusters with H₂O produced simultaneously in the direct laser vaporization, which lead to the production of various solvated magnesium oxide cluster ions as follows:Mg（H₂O）_m⁺（m=0, 1, 2, 3）, Mg（MgO）（H₂O）_m⁺（m=1, 2, 3, 4）, H（MgO）（H₂O）_m⁺ （m=0, 1, 2, 3, 4, 5, 6）, H（MgO）₂（H₂O）_m⁺（m=0, 1, 2, 3, 4, 5, 6）, H（MgO） 3（H₂O）_m⁺ （m=1, 2, 3, 4, 5, 6, 7）, H（MgO） 4（H₂O）_m⁺ （m=2, 3, 4, 5, 6, 7, 8）and H（MgO）₅（H₂O）_m⁺ （M=3, 4, 5, 6, 7, 8, 9）.The cluster ions are formed through many plausible growing paths made up of the growing processes and solvation processes of magnesium oxide cluster.The abundance distribution of the solvated clusters shows that there should exist a solvation shell.