Study of vaporization of LiI, LiI/C70, LiI/LiF/C70 from the Knudsen cell located into ionization chamber of the mass spectrometer

Abstract

The vaporization of LiI, LiI/C 70 and LiI/LIF/C 70 was studied using a Knudsen cell located in the ionization chamber of a magnetic sector mass spectrometer in the temperature range from 350 °C to 850 °C. The ion species, Li n I + (n = 2, 3, 4 or 6) were identified from the mixture LiI/C 70 , while the clusters Li n I + and Li n F + (n = 2, 3, 4, 5 or 6) were detected from a mixture LiI/LiF/C 70 . The intensities of Li n I + were higher than the emission of Li n F + cluster when the ratio of LiI to LiF was 2:1. By contrast, the emission of Li n F + is favored when the ratio of LiI to LiF was 1:2. These results show that the vaporization of a mixture LiI/LIF/C 70 from a Knudsen cell located in the ionization chamber of a mass spectrometer represents an efficient and simple way to obtain and investigate clusters of the type Li n X, X = F or I. In this work, it was also shown that the trends of the In (Intensity, arb. units) versus temperature for all Li n I + clusters below and above the melting point of LiI were not same. This suggested that the manner of formation of these clusters could be different due to changes in temperature.

Recent Progress on the Design, Characterization, and Application of Superalkalis

“…To date, the existence of simple superalkali molecules, such as OL 3 (L=Li, Na, K), ML 2 (M=F, Cl, Br, I; L=Li, Na, K), SLi 3 , Li 3 F 2 , Li 2 CN, and Na 2 CN have been confirmed by experiments –. These superalkalis are mainly detected by using the following mass spectrometric methods: laser ablation, electron impact ionization, surface ionization, 18d] thermal ionization,– Knudsen effusion cell, field desorption, spark source, secondary ion desorption, plasma desorption, and neutralization/reionization . In these experimental studies, the ionization energies of the resulting species are determined, mostly by photoionization, to characterize their superalkali characters.…”