The special features of the formation of molecular ions on the surface of tantalum

Thermal emission of singly charged positive molecular ions, mass 254, from the surface of a tantalum band was studied. Thermal emission appeared if, first, oxygen acted on a tantalum band at a temperature higher than 600°C, and then the band was held at room temperature. At the time of holding t longer than a minute, thermal emission linearly depended on \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \sqrt t $$\end{document}. The special features of thermal emission were explained by the presence of a critical temperature of tantalum close to 400°C, at which all the molecular ions were emitted from the surface. A new model of their formation was suggested.