Gas-phase high-temperature photoelectron spectroscopy: an investigation of the transition metals iron, cobalt and nickel

The helium I photoelectron spectra of iron, cobalt and nickel have been recorded in the gas phase. Bands associated with ionisation from the outermost 3d and 4s orbitals have been observed and estimates have been made of the sigma 3d : sigma 4s photoionisation cross section ratios recorded at right angles to the photon beam. For all three metals evidence for ionisation from excited electronic states has been detected in the observed spectra and for iron and nickel it was possible to estimate the effective excitation temperatures as (1500+or-200)K and (1600+or-200)K respectively.