Abstract: By 355 nm laser ablating a composite target prepared from metallic lithium and ZnOin high vaccum, a new hypermetallic oxide LiZnO⁺ ion, which consists of two heterometal atoms and oxygen atom, was observed by using a time-of-flight mass spectrometer for the first time. The time-of-flight positive ion mass spectra at different delay time between the accelerated electric field and laser pulse are investigated. It shows that the formation of LiZnO⁺ depends on the delay time, and the hypervalent ion LiZnO⁺ is observed obviously at the delay time from 7.5 to 17.5 μs. These results suggest that the ion molecular reaction between the ablated Li⁺ ions and ZnOin the laser plasma should be responsible for the formation of hypermetallic LiZnO⁺.

Key words: Hypermetallic molecules, Time-of-flight mass spectrometer, Laser plasma