We have constructed a high-resolution synchrotron-radiation angle-resolved photoemission (ARPES) spectrometer combined with a combinatorial laser molecular-beam epitaxy (laser MBE) thin film growth system in order to investigate the electronic structure of transition metal oxide thin films. An ARPES spectrometer GAMMADATA SCIENTA SES-100 was selected for the high-throughput and high-energy and angular-resolution ARPES measurements. A total energy resolution of 6.3 meV and a momentum (an angular) resolution of 0.02 Å−1 (0.2°) were obtained at a photon energy of 40 eV. The system is installed at the high-resolution vacuum-ultraviolet beamline BL-1C or the soft-x-ray undulator beamline BL-2C at the Photon Factory as an end-station. Another distinctive feature of this system is the direct connection from the spectrometer to a laser MBE chamber. Thin film samples can be transferred quickly into the photoemission chamber without breaking ultrahigh vacuum. Laser MBE is one of the best methods to grow thin films of many different transition metal oxides and to achieve well-ordered surfaces, which are indispensable for the ARPES measurements. The capabilities of the system and the importance of the in situ sample transfer between ARPES and laser MBE are demonstrated by studying the band structure of La0.6Sr0.4MnO3 thin films epitaxially grown on SrTiO3 substrates by laser MBE.

We report on the fabrication of terminating-layer-controlled La0.6Sr0.4MnO3 (LSMO) thin films and in situ characterization of the films using photoemission spectroscopy. The terminating layer of the LSMO films was changed from B to A site by inserting one atomic layer of SrO between the LSMO film and a TiO2-terminated SrTiO3(001) substrate. The successful control of the terminating layer was confirmed by measuring the angular dependence of core-level spectra. Detailed analysis of the Sr 3d core levels revealed considerable differences in chemical bonding states of Sr atoms in the surface regions of films with different terminating layers.

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Since the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye in 2011, there have been extensive discussions in various countries. This paper reviews the current situation in radiation protection of the ocular lens and the discussions on the potential impact of the new lens dose limit in Japan. Topics include historical changes to the lens dose limit, the current situation with occupational lens exposures (e.g., in medical workers, nuclear workers, and Fukushima nuclear power plant workers) and measurements, and the current status of biological studies and epidemiological studies on radiation cataracts. Our focus is on the situation in Japan, but we believe such information sharing will be useful in many other countries.

In conjugated organic molecules, the difference between the HOMO and LUMO Kohn-Sham eigenvalues is significantly smaller than the transport gap measured experimentally. We discuss here, within a local-orbital formulation of DFT, how this problem can be corrected using appropriate hybrid potentials, that add a fraction of Hartree-Fock exchange interaction in the DFT calculation. We illustrate this approach presenting calculations for two simple systems: H 2 and C 6 H 6 ; then, we discuss how to implement this hybrid approach in a general local-orbital calculation, adjusting the hybrid contribution to yield the correct experimental HOMO/LUMO energy gap for the molecule. We also consider the case of an organic molecule on a metal and analyze the effect of the molecule-metal interaction on the organic energy gap. In particular, we discuss how to introduce in this hybrid-potential scheme the effect of the image potential, and present results for the organic molecules PTCDA, TTF, benzene and pentacene on the metal surfaces Au(111), Ag(111) and Cu(111).