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Hard x-ray valence band photoemission spectroscopy (PES) is realized using high-energy and high-brilliance synchrotron radiation. High-energy (∼6 keV) excitation results in larger probing depths of photoelectrons compared to conventional PES, and enables a study of intrinsic electronic property of materials in actual device structures much less influenced by surface condition. With this technique, requirements for surface preparation are greatly reduced, if not eliminated. It is a nondestructive tool to determine electronic structure from surface to genuine bulk as shown by a study on SiO2/Si(100). Electronic structure modification related to the ferromagnetism in the diluted magnetic semiconductor Ga0.96Mn0.04N is also observed.

The influence of sodium on the band structure of MoS2(0001) and the comparison of the experimental band dispersion with density functional theory show excellent agreement for the occupied states (angle-resolved photoemission) and qualitative agreement for the unoccupied states (inverse photoemission spectroscopy). Na-adsorption leads to charge transfer to the MoS2 surface causing an effect similar to n-type doping of a semiconductor. The MoS2 occupied valence band structure shifts rigidly to greater binding with little change in the occupied state dispersion. Likewise, the unoccupied states shift downward, approaching the Fermi level, yet the amount of the shift for the unoccupied states is greater than that of the occupied states, effectively causing a narrowing of the MoS2 bandgap.

Lattice instability of off-stoichiometric Ni-Mn-Ga based ferromagnetic shape memory alloys with different valence electron concentrations (e/a’s) has been studied by utilizing hard X-ray photoelectron spectroscopy. Comparison of two alloys with different e/a’s suggests that a rigid band model is not applicable to explain the different martensitic transition temperatures. It is revealed that the specimen with larger e/a shows larger density of the Ni 3d eg states near the Fermi energy compared to specimen with lower e/a. The results can be reasonably explained by the band Jahn-Teller effect.

We have directly characterized the spin-polarized energy-band structures of Sb(111) near the Fermi level by spin- and angle-resolved photoemission spectroscopy. The results clearly indicate that the energy bands are spin-split due to the spin-orbit coupling and the broken space inversion symmetry.

Temperature-dependent electronic structures of RExC60 (where RE denotes Yb and Sm) films have been studied by high-resolution photoemission spectroscopy (PES). Our results indicate that Yb5C60 is the only metallic phase among all the phases in Yb doped C60 films. For the Sm fullerides, PES results show that there is no Sm valence transition during the negative thermal expansion in Sm2.75C60 below 32K. The Sm valence state in Sm2.75C60 films is nearly +2 at room temperature and remains stable in the films down to 16K. In addition, the negative thermal expansion effect does not result any distinct change in valence-band electronic structures of Sm2.75C60.

Mn L2,3 x-ray absorption and magnetic circular dichroism study has been performed on IV-VI ferromagnetic semiconductor Ge1-xMnxTe with different Mn compositions x=0.12, 0.32, 0.51, and 1. The absorption and dichroism line shapes are found to be almost independent of the Mn composition, suggesting that the local chemical environment of Mn atoms is the same for Ge1-xMnxTe with the wide range of x. On the basis of the configuration interaction analysis for a MnTe6 cluster, the electronic structure parameters such as the p-d hybridization and the p-d exchange constant have been estimated.

We have developed a compact retarding-type Mott spin polarimeter with a large collection angle at the Hiroshima Synchrotron Radiation Center and obtained a reliable value of the effective Sherman function by a self-calibration method. The spin polarization of secondary electrons was evaluated by extrapolation of the left-right scattering asymmetry at the zero energy-loss limit, which enabled us to obtain the effective Sherman function (Seff) and the figure of merit of our polarimeter at different operating conditions.

The optical design and mechanical solution for a soft x‐ray beamline BL‐7A in PF‐KEK for the energy range 10–1000 eV with a PGM are described. The optical characteristics of the beamline are tested with gas phase absorption and photoelectron spectroscopy.

A new VUV beamline at the Photon Factory ring that is designed to accept radiation emitted from an undulator is described. The characteristics of the undulator and all parts of the beamline; a front end, a mirror system, and two monochromators, are described in detail. The characteristics of optical elements in the beamline are also shown.

We have measured the optical‐emission spectra of the silane plasma as a function of the external magnetic field, together with the growth rate and vibrational spectra of the resulting a‐Si:H films. The optical‐emission intensities of the reactive species SiH, H2, and H produced in the plasma are appreciably affected by the magnetic field, and the corresponding change in the hydrogen bonding of the deposited films is interpreted in terms of chemical reaction among the species.