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Takanishi Y.,Kyoto University | Ohtsuka Y.,Tokyo Institute of Technology | Takahashi Y.,Nihon University | Iida A.,Institute of Material Structure Science
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

We studied the local layer structure in the B2 phase of bromine-substituted bent-core liquid crystals in the cell geometry using microbeam resonant x-ray scattering. In the homochiral state of B2 phase, the 3/2 order satellite peak was observed only when the incident x-ray energy is at the K absorption edge of bromine. This result clearly indicates that the B2 homochiral domain forms two-layer superlattice in adjacent layers, the same as in the rodlike Sm- CA phase. The work reports on microbeam resonant x-ray scattering experiment from the local layer of the bent-core liquid crystal in the device geometry. Moreover, we can say that bromine is also useful for the analysis of the superstructure of soft materials using resonant x-ray scattering. © 2010 The American Physical Society.


Takanishi Y.,Kyoto University | Nishiyama I.,Dainippon Ink and Chemicals | Yamamoto J.,Kyoto University | Ohtsuka Y.,Tokyo Institute of Technology | Iida A.,Institute of Material Structure Science
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2013

We found a subphase with a six-layer periodicity which appears between the ferroelectric SmC* and the antiferroelectric SmC A *(qT = 0) phases. The six-layer periodic structure is directly determined by the microbeam resonant x-ray scattering measurement. Furthermore, considering the dielectric constants, this phase was found to be ferrielectric, assigned as SmCA *(q T = 2/3). This subphase indicates the importance of the competition between the ferro- and the antiferroelectric phases and, in that point, it is essentially different from the previously observed six-layer phase. The relation between current theories and our present experimental results has been studied and discussed. © 2013 American Physical Society.


Diacomanolis V.,University of Queensland | Ng J.C.,University of Queensland | Sadler R.,Griffith University | Harris H.H.,University of Adelaide | And 2 more authors.
AIP Conference Proceedings | Year: 2010

This study examines the molecular form of cadmium (Cd) present in mine wastes by X-ray Absorption Spectroscopy (XAS; Cd>20 mg/kg) using the K-edge of Cd at the Photon Factory Advanced Ring (PF-AR), NW10A beam line at KEK-Tsukuba-Japan. Mine waste materials and zinc concentrate were analyzed for Cd by ICPMS prior to undertaking XAS (range 21-452 mg/kg). Model compounds (CdO, Cd(OH)2, CdCO3, Cdacetate, CdS, Cdstearate, CdDEDTC) and samples were examined in solid form at 20 K. The XANES spectra showed similar E max values for both model compounds and samples. The EXAFS showed that Cd-S in CdS, gives a flatter spectrum in the extended region compared to Cd-O found with CdCO3, CdO and Cd Stearate. Linear combination fitting with model Cd compounds did not give clear assignments of composition, indicating that more detailed EXAFS spectra is required as mineral forms containing Cd were present rather than simple Cd compounds such as CdCO3. The Cd bond for a single shell model in mine waste sample matrices appears to be either Cd-O or Cd-S, or a combination of both. Comparison of molecular data from the XAS studies with bioaccessibility data giving a prediction of bioavailability for mine waste materials provides useful information about the significance of the cadmium form as a contaminant for health risk assessment purposes. © 2010 American Institute of Physics.


Diacomanolis V.,University of Queensland | Ng J.C.,University of Queensland | Sadler R.,Griffith University | Harris H.H.,University of Adelaide | And 2 more authors.
AIP Conference Proceedings | Year: 2010

Direct examination by XANES and EXAFS of metal bonding in tissue can be demonstrated by examining cadmium uptake and bonding in animal tissue maintained at cryogenic temperatures. XANES at the K-edge of cadmium were collected at the Photon Factory Advanced Ring (PF-AR), NW10A beam line at KEK-Tsukuba-Japan. Rats fed with 1g mine waste containing 8-400 mg/kg cadmium per 200g body weight (b.w.) or dosed by oral gavage with either cadmium chloride solution alone (at 6 mg/kg b.w.) or in combination with other salts (As, Cu or Zn), 5 days/week for 6 weeks, had 0.1-7.5 and 8-86 mg/kg cadmium in the liver or kidney, respectively. Rats given intraperitoneally (ip) or intravenously (iv) 1-4 times with 1 mg/kg b.w. cadmium solution had 30-120 mg/kg cadmium in the liver or kidney. Tissues from rats were kept and transferred at cryogenic temperature and XANES were recorded at 20 K. The spectra for rat liver samples suggested conjugation of cadmium with glutathione or association with the sulfide bond (Cd-S) of proteins and peptides. EXAFS of rat liver fed by Cd and Zn solutions showed that Cd was clearly bound to S ligands with an inter-atomic distance of 2.54 Å for Cd-S that was similar to cadmium sulfide with an inter-atomic distance of 2.52 Å for Cd-S. Liver or kidney of rats fed with mine wastes did not give an edge in the XANES spectra indicating little uptake of cadmium by the animals. Longer and higher dosing regimen may be required in order to observe the same Cd-S bond in the rat tissue from mine wastes, including confirmation by EXAFS. © 2010 American Institute of Physics.


Suzuki K.,Gunma University | Ito M.,Gunma University | Tsuji N.,Gunma University | Tsuji N.,Japan Synchrotron Radiation Research Institute | And 14 more authors.
e-Journal of Surface Science and Nanotechnology | Year: 2011

An experimental system of X-ray magnetic diffraction (XMD) is developed on BL3C at the Photon Factory (PF) of High Energy Research Organization (KEK). We applied this upgraded XMD experimental system to 3d- and 4f-electron ferromagnet, YTiO3 and CeRh3B2, respectively. In YTiO3 we successfully obtained spin magnetic form factor for 31 reciprocal lattice points. The observed spin magnetic form factor suggests anisotropic spin density distribution in real space. In CeRh3B 2 we succeeded in measuring spin and orbital magnetic form factor separately. We found that the dominant part of the magnetic moment is the orbital component in CeRh3B2. © 2011 The Surface Science Society of Japan.

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