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Time-resolved magneto-optical Kerr effect (MOKE) measurement was demonstrated on a sample of the Au/Fe/Au heterostructure with the Fe layer of 0.35nm thickness under Fe M-edge resonance condition. An ultrabrilliant free electron laser (FEL) in the soft X-ray range was facilitated for the detection of transient signals of resonant MOKE from the ultrathin Fe film. A variation in the Kerr rotation angle was successfully observed on the femtosecond timescale. This technique enables us to reveal the transient magnetization dynamics of such a-few-monolayer magnetic films, which promote the development of spintronic devices.

A photoemission electron microscopy measurement system on insulating samples was established at the BL17SU beamline of SPring-8 by utilizing an Au pattern evaporation technique combined with photon-induced surface modification., The observation method of photoemission electron microscopy (PEEM) on insulating samples has been established in an extremely simple way. Surface conductivity is induced locally on an insulating surface by continuous radiation of soft X-rays, and Au films close to the area of interest allow the accumulated charges on the insulated area to be released to ground level. Magnetic domain observations of a NiZn ferrite, local X-ray absorption spectroscopy of sapphire, high-resolution imaging of a poorly conducting Li0.9CoO2 film surface, and Au pattern evaporation on a fine rock particle are demonstrated. Using this technique, all users’ experiments on poorly conducting samples have been performed successfully at the PEEM experimental station of SPring-8.

We present an x-ray spectromicroscopic investigation of single-crystalline magnetic FeMn/Co bilayers on Cu(001), using x-ray magnetic circular dichroism and x-ray magnetic linear dichroism (XMLD) at the Co and Fe L-3 absorption edges in combination with photoelectron emission microscopy. Using the magnetic coupling between the ferromagnetic Co layer and the antiferromagnetic FeMn layer, we are able to produce magnetic domains with two different crystallographic orientations of the magnetic easy axis within the same sample at the same time. We find a huge difference in the XMLD contrast between the two types of magnetic domains, which we discuss in terms of intrinsic magnetocrystalline anisotropy of XMLD of the Co layer. We also demonstrate that due to the high sensitivity of the method, the small number of induced ferromagnetic Fe moments at the FeMn-Co interface is sufficient to obtain magnetic contrast from XMLD in a metallic system.

The method to deduce the atomic orbitals constituting a valence band from two-dimensional photoelectron angular distribution (PEAD) (called ODAD: orbital determination from angular distribution) is fully discussed. The two-dimensional PEAD pattern obtained by using linearly polarized light is characteristic of the initial atomic orbitals. If the initial electronic state is localized and a wide-angle two-dimensional PEAD pattern is observed, the component ratio of atomic orbitals can be deduced by fitting the observed PEAD with calculated patterns. When only a limited area is observed by the effect of band dispersion, we can change the polar angle θ p or the azimuthal angle o p of the sample with respect to the incident photon so that we can get enough information. Even and odd symmetries are easily distinguished when we measure the o p dependence of the photoelectron intensity. The θ p dependence at a special direction (θ k , o k )=(45, 35) is proposed to distinguish all atomic orbitals.

The Fermi surface of the noncuprate superconductor Sr 2 RuO 4 has been studied in detail by two-dimensional angle resolved photoelectron spectroscopy (2D-ARPES) using a display-type electron spectrometer and a linearly polarized synchrotron radiation. The existence of the large Fermi surfaces agrees with previous band calculations and conventional ARPES measurements. From the comparison of the observed photoelectron intensity distribution of the Fermi surface with that of the simulation for atomic orbitals, the symmetry of the atomic orbitals composing the Fermi surfaces is revealed to be the d e ; d x y , d y z , d z x -like in contrast to the d x 2 - y 2 -like orbital in the cuprate high- T c super conductor. The possibility of the existence of the extended van-Hove singularity just below the Fermi level, which was suggested by recent conventional ARPES measurements, is also discussed.

The shape of the Fermi surface of the Sr2RuO4, the first noncuprate superconductor, has been directly observed by two-dimensional angle resolved photoelectron spectroscopy (2D-ARPES) technique using a display-type hemispherical mirror analyzer. The gross shape of the Fermi surface agrees with previous band calculations. The photoelectron angular distribution pattern of the Fermi level shows that the Fermi surface is composed of orbitals withdxy,dyz, anddzx-like symmetries which agree well with those predicted by previous band calculations and are in contrast todx2−y2 symmetry of thehigh-TC superconductors.

We have directly observed the Fermi surface of Bi2Sr2CaCu2O8(Bi(2212)) by a display-type angle-resolved photoelectron spectrometer. The experiment was done at room temperature by using linearly-polarized synchrotron radiation (SR). The photon energy was 32 eV and the incident angle of the photon was perpendicular to the sample surface. Photoelectron angular distribution (PEAD) patterns were measured at various azimuthal angles φ from 0° to 135° in steps of 22.5°, where φ is the angle between the direction of the electric vector of the photon and the sample Cu O bond direction. The observed shape of the Fermi surface is consistent with the band calculation by the FLAPW method [S. Massidda et al., Physica C 152 (1998) 251]. We confirmed the symmetry of the atomic orbital constituting the Fermi surface to bedx2−y2 by ‘orbital determination by angular distribution’ (ODAD).

The benefit of combining soft X-ray magnetic circular dichroism and photoelectron microscopy is demonstrated by applying this combination to the observation of the magnetic domain structures of rectangular microstructures. The size and aspect-ratio dependence of the transformation of the domain structures by magnetic field pulses is investigated. The switching mechanism, which is very important in the application to magnetic storage, is discussed in terms of transformation between saturated and vortex domain structures.