Density of states of ferromagnetic and paramagnetic Ni and Fe studied by photoelectron spectroscopy with 21.2- and 40.8-eV photon energies

We present in this paper photoemission measurements on Ni and Fe which could partly be viewed as an extension of the measurements on nickel by Rowe and Tracy with $\hslash \omega <5\mathrm{}$ eV and by Pierce and Spicer with $\hslash \omega <11.7\mathrm{}$ eV at temperatures below and above the Curie temperature. We use photon energies of 21.2 and 40.8 eV which give electron energy distributions which, in a more direct way, show the shifts expected from the early band model of ferromagnetism when the temperature is varied through the Curie temperature. Iron is included because the shifts should be larger than for nickel owing to the larger exchange splitting. However, no such energy shifts are detected.