Work function of binary alloys

By utilizing the ®eld emission method, we have studied the composition dependence of work function in NiCu and PtRh alloys. In PtRh alloys, we ®nd that the work function falls below the linear interpolation, in agreement with the experimental results on AgAu alloys [Fain and McDavid, Phys. Rev. B 9 (1974) 5099]. On the other hand, the work function of NiCu alloys is found to show little systematic deviation from the linear interpolation. The observed negative deviation in PtRh alloys is not compatible with a simple theoretical prediction based on the electronic density of states. # 2001 Elsevier Science B.V. All rights reserved.