Quasi-one-dimensional magnetic interactions and conduction electrons in EuCu and EuAu with the characteristic hexagonal structure

Matsuda, Shinya*; Ota, Joji*; Nakaima, Kenri*; Iha, Wataru*; Gochi, Jun*; Uwatoko, Yoshiya*; Nakashima, Miho*; Amako, Yasushi*; Honda, Fuminori*; Aoki, Dai*; et al.

Philosophical Magazine, 100(10), p.1244 - 1257, 2020/04

https://doi.org/10.1080/14786435.2019.1708498

Mechanism of state-specific enhancement in photon-stimulated desorption as studied using a polarization-dependent technique

Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Wu, G.*; Kitajima, Yoshinori*

Surface Science, 593(1-3), p.310 - 317, 2005/11

https://doi.org/10.1016/j.susc.2005.06.076

Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids have been investigated. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed chlorobenzene.

Substitution effect on orientation of organosilicon compounds (CH)SiX (X = F, Cl, Br, I, NCO) as studied using NEXAFS spectroscopy

Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Nath, K. G.*; Uddin, M. N.*

Journal of Physics; Condensed Matter, 17(36), p.5453 - 5466, 2005/09

https://doi.org/10.1088/0953-8984/17/36/002

The orientation nature of multilayer organosilicon compounds has been investigated by measuring the dependence of the Si K-shell near-edge X-ray absorption fine structures (NEXAFS) on the polarization angle. Two approaches helped to elucidate the orientation mechanism: the substitution effect and the deposition-rate dependence. The orientation angles of Si-X bond axes were obtained for trimethylsilyl halides, (CH)SiX (X =F Cl Br I NCO, condensed on Cu(111) at a low (82 K) temperature: the angles are 60, 73, 61, 55, and 55 degrees with respect to the surface normal, for X =F, Cl, Br, I, and NCO, respectively. Chloride (X =Cl) produces the most parallel tilt angle. The specific orientation nature of chloride is attributed to its strong dipole moment as well as the regular tetrahedron shape of the molecule. The molecular volumes calculated verify this view. Furthermore, deposition rates are found to greatly influence the growth manner: namely, high deposition rates led to a slightly perpendicular orientation of Si-X bond axis.

RHEED observation of BaTiO thin films grown by MBE

Yoneda, Yasuhiro; Sakaue, Kiyoshi*; Terauchi, Hikaru*

Surface Science, 529(3), p.283 - 287, 2003/04

https://doi.org/10.1016/S0039-6028(03)00361-3

Ferroelectric BaTiO thin filmwith a thickness of 10ML were epitaxally grown on SrTiO (001) substrate by very slow deposition using MBE. The investigation were carried out by two growth methods: (i) codeposition and (ii) alternate deposition. In-situ observation of RHEED confirmed that an epitaxial cube-on-cube structure was prepared. After the deposition, X-ray diffraction measurements were carried out. The 10-ML-thick BaTiO films were highly -axis oriented single crystals with good film quality.

Preparation of epitaxial TiO films by PLD for photocatalyst applications

Yamaki, Tetsuya; Sumita, Taishi; Yamamoto, Shunya; Miyashita, Atsumi

Journal of Crystal Growth, 237-239(Part1), p.574 - 579, 2002/04

Pulsed laser deposition (PLD) with a KrF excimer laser was used to prepare epitaxial TiO films on a (0001) sapphire substrate. The crystalline structure and surface morphology of the films were then investigated as a function of the laser power density in the PLD. X-ray diffraction and Raman spectroscopy results showed that the films were composed of the (100) oriented rutile phase with a small amount of the (001) oriented anatase. The anatase-to-rutile ratio in such phase-mixed films was controlled by the laser power; the ratio increased as the power density decreased. From atomic force microscopy observations, the film deposited at the lowest power was found to have a rough surface consisting of coarse grains. This film exhibited the best photocatalytic performance during the decomposition of the organic dyes possibly due to the maximum relative content of anatase and the large surface area.

Surface structure of laser ablated C pellet

Yoda, Osamu; Miyashita, Atsumi

Journal of Applied Physics, 75(10), p.5450 - 5452, 1994/05

https://doi.org/10.1063/1.355705

no abstracts in English

Stress Intensity Factor Analyses of Surface Cracks in Three-Dimensional Structures

*; ; *; *

JAERI-M 83-189, 44 Pages, 1983/11

JAERI-M-83-189.pdf:1.05MB

no abstracts in English

Edge structures of montmorillonite; A Density functional theory study

Sakuma, Hiroshi*; Tachi, Yukio; Yotsuji, Kenji; Kawamura, Katsuyuki*

no journal, , 

Clay minerals are good adsorbents of many toxic elements of molecules in natural environment, because of their large surface areas and their high affinity to organic and inorganic materials. The adsorption sites of ions and molecules on the basal planes can be estimated by experiments and computer simulations based on the simple surface structure. While the adsorption of ions and molecules on the edge planes of clay minerals is poorly understood due to the absence of established model of the edge structures. In this study, the edge structures of montmorillonite were examined by the first-principles calculations based on the density functional theory. The effect of isomorphous substitution, layer charge, and positions of interlayer cations was evaluated for four different edge planes by calculating the surface energy. The acidity constant of the edges were calculated by an empirical method. We will discuss possible adsorption sites of cations on these edges.