Work function and secondary emission studies of various Cu crystal faces

Abstract

The work function and its temperature dependence has been measured for the 〈100〉, 〈110〉, 〈111〉, 〈112〉 as well as 13 other Cu crystal planes. The results, obtained with two types of incident electron beam techniques in this experiment, are in good agreement with recent photoelectric and contact potential difference results reported on ion-sputter-cleaned surfaces. Variation in secondary emission for different crystal faces was found to be determined primarily by the work function changes of the different crystals and not so much by the bulk lattice orientation. It was also observed that the secondary electrons are not as dependent on the velocity constraints imposed by the Bragg condition as are the electrons having thermal energies.