The determination of the thermionic work function of nickel by a new method

I. The work function of nickel was determined thermionically and found to be 5.03 +/- .05 volts. The constant A was found to be 1.38 x 103 amps/cm2deg 2;II. A new method was developed for determining the thermionic work function of metals. It differs from the conventional method in the following respects: (1) The metal is in the form of a rough sphere. (2) It is heated by electron bombardment from an auxiliary filament. (3) Measurements are made as the metal cools. (4) The emission current charges a condenser which is discharged through a galvanometer at pre-determined times. (5) The temperature is measured by a Pt, Pt + 10% Rh thermocouple spotwelded to the sample. (6) The values of the constants are obtained from this equation, log&parl0;T2/SQ&parr0;=log 2.3/aA+b/2.3T in which T is the absolute temperature, S is the slope of the log Q, t curve in which t is the time of cooling, Q is the charge as measured from the lowest temperature to which the sample is cooled, a is the area of the sample and b and A are the constants sought for