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The surface electronic structure of 1500-angstrom-thick Fe3O4(100) films is investigated by spin0-resolved photoemission spectroscopy with vacuum ultraviolet synchrotron radiation. The top of the valence band is found to be negatively spin polarized, with a value of approximately -50 percent, thus pointing towards the localized nature of the 3d states in the system.

Spin- and angle-resolved photoemission of Cu on Co(100) and Ag on Fe(100) indicates the spin-polarization of the sp-derived states of noble metals in contact with these magnetic materials. The quantization of bulklike states gives a quantum-well picture for films with few monolayer thickness, thus describing sp-state development. These states hybridize with the bands in the low coverage regime, altering the conduction electron bands.

The thickness dependent spin-polarized electronic structure of thin and ultrathin films of Gd is distinguished by changes in the critical lambda exponent in the formalism of finite size scaling. The reduced critical exponent is correlated to increased prominence of surface magnetic structures, and the increasing paramagnetic-like bulk behaviour.

Photoemission, inverse photoemission and spin-polarized photoemission has been used to study the electronic structure of strained and unstrained gadolinium Gd(0001). Strain led to a shift of the occupied majority and unoccupied minority surface states, consistent with a phase accumulation model. There was a strain induced shift of the minority spin surface state over the Fermi level.

In the unbaked vacuum systems of extreme ultraviolet (EUV) lithography steppers, oxide formation and carbon growth on Mo/Si multilayer mirrors (MLMs) are competing processes leading to reflectivity loss. A major contribution to this mirror degradation is a series of surface reactions that are thought to be driven in large part by photoemitted electrons. In this paper, we focus on the resonance effects in photoemission from Mo/Si MLMs protected by thin TiO2 cap layers. In the vicinity of the resonant energy of the mirror, the energy flux of the EUV radiation forming standing wave oscillates throughout the multilayer stack. As a result, light absorption followed by the emission of photoelectrons becomes a complex process that varies rapidly with depth and photon energy. The electron emission is characterized as a function of the EUV photon energy, the angle of incidence, and the position of the standing wave with respect to the solid/vacuum interface. In our experiments, the position of the standing wave was controlled both by deliberately varying the thickness of the Si terminating layer (of the Mo/Si stack) and by depositing C films of various thicknesses on the TiO2. The experimental data are compared with model simulations to examine the changes in photoemission yield due to the presence of carbon and to the changes in the position of the standing wave. We find that carbon deposition can have a dramatic impact on the yield and, therefore, on the rates of electron mediated reactions at the surface. [ABSTRACT FROM AUTHOR]

We present measurements of element- and time-resolved ferromagnetic resonance (FMR) in magnetic thin films at gigahertz frequencies via an implementation of time-resolved x-ray magnetic circular dichroism (TR-XMCD). By combining TR-XMCD and FMR, using a rf excitation that is phase locked to the photon bunch clock, the dynamic response of individual layers or precession of individual elements in an alloy can be measured. The technique also provides extremely accurate measurements of the precession cone angle (to 0.1°) and the phase of oscillation (to 2°, or ∼5 ps at 2.3 GHz). TR-XMCD combined with FMR can be used to study the origins of precessional damping by measuring the relative phase of dissimilar precessing magnetic moments. We have used the technique to measure the response of specific elements and separate layers in several alloys and structures, including a single Ni81Fe19 layer, a pseudo-spin-valve structure (Ni81Fe19/Cu/Co93Zr7), magnetic bilayers consisting of low damping (Co93Zr7) and high damping (Tb-doped Ni81Fe19) layers joined across a common interface, and elemental moments in Tb-doped Ni81Fe19. [ABSTRACT FROM AUTHOR]

The surface electronic structure of 1500-Å-thick Fe3O4(100) films has been investigated by spin-resolved photoemission spectroscopy with vacuum ultraviolet synchrotron radiation. The films, epitaxially grown on MgO(100) substrates using plasma-assisted molecular-beam deposition, are briefly exposed to air during transfer to the photoemission chamber. It is shown that clean surfaces of Fe3O4 films after exposure to air can be recovered through mild annealing in an oxygen atmosphere. The presence of the characteristic Verwey transition, as detected in the valence-band photoemission spectra, provides evidence for the excellent electronic quality at the surface of these films. The top of the valence band is found to be negatively spin polarized, with a value of ≈-50%; this result strongly points towards the localized nature of the 3d states in this system. [ABSTRACT FROM AUTHOR]

Time-resolved x-ray magnetic circular dichroism (TR-XMCD) is combined with element- and time-resolved ferromagnetic resonance (FMR) for measuring the dynamic response of individual layers ore precession of individual elements in magnetic alloys. The measurements have revealed a frequency dependent phase lag that has developed between a high damping layer and a low damping layer.

Experimental techniques to measure magnetization precession of individual layers in a 'spin-valve' trilayer are presented. The efficacy of two experimental configurations for measurements namely pulsed-field time-resolved X-ray magnetic circular dichroism (tr-XMCD) and resonant-field tr-XMCD are compared and it is found that data quality is superior in resonant-field transmission measurements.

We present experimental techniques to measure magnetization precession of individual layers in a “spin-valve” trilayer. Precessional motions of individual Ni81Fe19 and Co93Zr7 layers have been separated in Ni81Fe19/Cu/Co93Zr7 using ±45 ps time-resolved x-ray magnetic circular dichroism (tr-XMCD) at Fe and Co edges. We compare the efficacy of two experimental configurations in this paper. Pulsed-field tr-XMCD measurements in reflectivity are compared with resonant-field tr-XMCD measurements in transmission. Despite the order of magnitude larger angles of precession excited in pulsed-field reflectivity measurements, data quality is found to be superior in resonant-field transmission measurements. Relative roles of sample preparation and timing jitter in the different techniques are discussed. [ABSTRACT FROM AUTHOR]

Studies the finite size scaling behavior for increasing thinner films of strained gadolinium (Gd). Effect of distinct magnetic properties of film surface on the finite size scaling behavior of thin films and deviations; Features of the spin-polarized valence-band photoemission spectra of the strained Gd films.