E.A. Seddon

The adsorption and decomposition of chromium hexacarbonyl on Pd(100)

Abstract Chromium hexacarbonyl [Cr(CO)6] was physisorbed on the Pd(100) surface, and the molecular orientation was determined using reflection-absorption infrared spectroscopy (RAIRS). The thermal decomposition of the compound was observed, by the indirect observation of a modified surface morphology, which caused the adsorption of energetically unfavourable μ1-CO and influenced the growth and structure of subsequently adsorbed Cr(CO)6 layers.

Element specific spin-resolved densities of states in amorphous Fe75B25 probed with a synchrotron radiation source

The partial spin-dependent densities of states (DOS) of both the iron and the boron in Fe–B amorphous magnetic alloys have been determined from spin-resolved photoemission using a synchrotron radiation source. The spin-integrated energy distribution curves (EDCs), polarization spectra and the spin-resolved EDCs show distinct differences between 15 and 40 eV photon energies due to strikingly different photon energy dependencies of the cross sections of Fe-d and B-p states. The B-p states were found to hybridize with Fe-d states and occupy a binding energy range of about 1–5.5 eV with a negative polarization; i.e., the B moment is “antiferromagetically” coupled with that of the Fe-d moment.

Spin-polarized photoemission of

The first spin-resolved photoemission experiment on an iron - boron amorphous alloy using a synchrotron source is presented. The experimental spin polarization of the d band of has been compared with three theoretical predictions and found to be in best agreement with self-consistent spin-polarized calculations based on a supercell LMTO approach. The observed average spin polarization of the valence band is approximately twice that of 10 eV secondary electrons. Hysteresis loops for determined from the 1 eV and 20 eV secondary-electron asymmetry are similar to those determined using the magnetooptic Kerr effect, but show a lower coercivity. The differences are attributed to a combination of different sampling depths of the two techniques and to the surface inhomogeneity of the sample.

The spin-dependent electronic structure of amorphous magnetic alloys

Spin-resolved photoemission from FeB and CoB binary amorphous alloys has been measured using, for the first time, a synchrotron radiation source. A comparison of the experimental results with several ab initio calculations on two model systems Fe80B20 and Co77B23 shows that the spin-resolved photoemission provided a critical test of theoretical models, and gives insight into the spin-dependent electronic structures of these materials.

Spin polarized photoemission from amorphous alloy surfaces

Abstract Recent results on spin polarized photoemission and photon excited secondary electron emission from the surfaces of ferromagnetic amorphous alloys Fe B, Co B and Fe Y are reviewed. Spin resolved density of states calculations suggest that the spin polarization profile is very sensitive to the theoretical model chosen, but experiments demonstrate that the spin up density dominates at the Fermi edge in the iron-based alloys, while the spin down density is greater in the cobalt alloy. Variation of photon energy from 15–110 eV allows polarization of sp states to be probed as well as d states and evidence for contributions to the magnetic moment from Y in Fe 60 Y 40 and B in Co 77 B 23 are examined. Photon excited secondary electrons provide a flexible monitor of surface magnetization: relative contributions to the polarization from spin polarization in the conduction band and spin dependence of the mean free path are separated by studying the variation of electron polarization with the kinetic energy of emission.

Amorphous alloys as secondary standards for electron spin polarimetry

The surface magnetism of as-cast and field annealed amorphous in ribbon form has been studied by spin-polarized secondary electron spectroscopy, by recording energy-resolved spin asymmetry hysteresis loops and by scanning electron microscopy with polarization analysis. Large lateral variations in surface magnetization have been detected, indicating that , in particular, and ferromagnetic melt-spun ribbons, in general, are not suitable as standard sources of polarized electrons. Deposition of an iron film onto the did not result in a more uniform surface but rather served to emphasize the substrate magnetic structure. Thus utilization of ferromagnetic melt-spun amorphous alloys as substrates for the growth of thin magnetic films should be undertaken with caution.