ELECTRON WORK-FUNCTIONS OF LEAD, SILVER, AND THALLIUM AZIDES

The work functions of lead, silver, and thallium azides were determine d by a modified Kelvin method. Contact potential difference was measur ed over a wide range of pressures (1.3 x 10(5)-1 x 10(-5) Pa) after he at treatment between 290 and 390 K. The reference electrodes used were made of platinum, aluminum, lead, silver, sodium, cadmium, nickel, in dium, and copper. It was found that a decrease in pressure or an incre ase in heat-treatment temperature has a pronounced effect on the conta ct potential difference in the azide-metal systems. The major cause of this effect is a decrease in the surface potential of lead, silver, a nd thallium azides as a result of the surface adsorption of donor and acceptor gas molecules.