Abstract
Optical plasma-resonance absorption of fcc Co island films consisting of fcc Co particles smaller than about 300 Å in diameter was measured in the photon energy region from 0.5 to 6.5 eV. Comparison of the broadening and the location of this absorption with those of Ni island films shows that the d character of conduction electrons of fcc Co is stronger than that of Ni, and that the number of conduction electrons per atom of fcc Co is large compared to that of Ni. The difference in the character can qualitatively be attributed to the difference in the s-d hybridization, which is larger in fcc Co than in Ni. The difference in the number may be due to the difference in the s-d hybridization.