Using hard x-ray (HX; hν = 5.95 keV) synchrotron photoemission spectroscopy (PES), we study the intrinsic electronic structure of La1−xSrxMnO3 (LSMO) thin films. Comparison of Mn 2p corelevels with Soft x-ray (SX; hν ∼ 1000 eV) -PES shows a clear additional well-screened feature only in HX-PES. Take-off-angle dependent data indicate its bulk (≥ 20Å) character. The doping and temperature dependence track the ferromagnetism and metallicity of the LSMO series. Cluster model calculations including charge transfer from doping induced states show good agreement, confirming this picture of bulk properties reflected in Mn 2p core-levels using HX-PES.PACS numbers: 71.30.+h, 78.20.Bh Hole-doped manganese oxides with a perovskite structure of Re 1−x Ae x MnO 3 (Re and Ae being trivalent rare earth : Nd, Pr, Sm, etc. and divalent alkaline earth elements : Ca, Sr, Ba, respectively) exhibit a rich phase diagram originating in complex collective phenomena due to interplay among spin, charge, orbital, and lattice degrees of freedom [1,2]. Among the manganites, La 1−x Sr x MnO 3 (LSMO) is a prototypical series showing the largest one-electron bandwidth and accordingly, is less significantly affected by electron-lattice and Coulomb correlation effects [2]. The parent compound LaMnO 3 is an antiferromagnetic (AFM) insulator which becomes, on hole-doping induced by substitution of Sr for La, a ferromagnetic (FM) metal [3] exhibiting colossal magnetoresistance (CMR). The optimal doped compound (x = 0.4) exhibits the highest Curie temperature (T C ) of 360 K among manganites and a half-metallic nature [4]. Further hole-doping induces a magnetic transition, transforming the FM metal to an AFM metal phase for x > 0.5 [5]. In the case of thin films, the critical temperature and resistivity change slightly compared to the bulk materials due to the strain from the substrate, but the qualitative physical properties are similar to the bulk materials, provided the films are at least ∼ 10 unit cells (∼ 30Å) thick [6,7,8,9].In particular, high-quality bulk and thin films of the LSMO series do not exhibit charge order and are also free of micro-and nano-scale phase separation phenomena seen in the La-Ca, Nd-Sr and Pr-Sr manganites [2]. However, ultra thin films of LSMO (i.e. < 30Å or 10 unit cell thickness) are known to show a suppression of metallicity, ferromagnetic T C and magnetization [6,7]. In order to clarify the origin of these unusual physical properties, it is important to investigate the electronic structure of LSMO with a depth sensitive probe. Photoemission spectroscopy (PES) has long played a central role in studying the electronic structure of strongly correlated electron systems including manganese oxides [9,10,11,12,13,14]. Temperature dependent half-metallic ferromagnetism, charge and orbital ordering, and its connection with the electronic structure and colossal magnetoresistance of the manganites have been clarified [11,12,13]. Nevertheless, the change in the Mn 2p spectra of manganese oxides with hole doping is still not...

A first focusing test of the undulator radiation at SPring-8 has been done using two types of x-ray refractive lenses in thin glass capillaries. One (lens No. 1) contained bubbles in a glue whereas the other (lens No. 2) contained bubbles in glycerol. The capillaries had inner diameters of 0.2 and 0.8 mm, respectively. Using x rays of 17–18 keV, the undulator source image was investigated at the focal plane. The spherical aberrations and the field distortions were carefully examined by taking the images of a gold mesh. Lens No. 1 had an advantage of high transmissivity in the hard x-ray region (18% at 18 keV) and high tolerance to severe radiation damage, e.g., ∼5×1012 photons/s/0.03 mm2 of the 18 keV x rays for an exposure time of 1 h. On the other hand, lens No. 2 had an advantage of a large aperture, 0.8 mm, and a small field distortion, e.g., less than 10% inside a diameter of 300 μm.

Microfocusing of 100 keV x ray with a sputtered-sliced Fresnel zone plate (ss-FZP) has been performed at the 250-m-long beamline (20XU) of SPring-8. The ss-FZP with an outermost zone width 0.16 μm which is composed of 70 layers of alternating Cu and Al layers and having thickness ∼180 μm was fabricated and characterized. The minimum focal spot size attained for the first order focal beam was 0.5 μm with a focal distance 900 mm at a photon energy 100 keV. The total flux of the microprobe was ∼2×106 photons s−1 μm−2.