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Takahiro, Katsumi*; Ninakuchi, Yuki*; Kawaguchi, Kazuhiro; Isshiki, Toshiyuki*; Nishio, Koji*; Sasase, Masato*; Yamamoto, Shunya; Nishiyama, Fumitaka*
Applied Surface Science, 258(19), p.7322 - 7326, 2012/07
Times Cited Count:2 Percentile:10.02(Chemistry, Physical)A nanometer-sized metallic particle embedded in a transparent dielectric exhibits a nonlinear susceptibility, and going to be applied to nonlinear optical devices. In the present study, well-ordered arrangements of Ag nanoparticles have been found for Ag-implanted SiO. Thermally grown SiO on Si were implanted with 350 keV-Ag ions to fluences of 0.37-1.2 10 ions/cm. Cross-sectional transmission electron microscopy and scanning transmission electron microscopy reveal the presence of a two-dimensional array of Ag nanoparticles of 25-40 nm in diameter located at a depth of 130 nm, together with the self-organization of tiny Ag nanoparticles aligned along the SiO/Si interface. X-ray photoelectron spectroscopy and X-ray diffraction confirm the stability of these Ag nanoparticles embedded in the SiO/Si is found to be stable against oxidation and sulfidation when stored in ambient conditions for more than one and a half year.
Takahiro, Katsumi*; Terai, Atsushi*; Kawatsura, Kiyoshi*; Naramoto, Hiroshi; Yamamoto, Shunya; Tsuchiya, Bun*; Nagata, Shinji*; Nishiyama, Fumitaka*
Japanese Journal of Applied Physics, Part 1, 45(3A), p.1823 - 1825, 2006/03
Times Cited Count:2 Percentile:8.72(Physics, Applied)It is found that the surface charging during Rutherford backscattering spectrometry (RBS) of insulating sapphire samples enables us to measure the charge-state distribution of probing ions backscattered at the sapphire surface. For Cu/Au-deposited AlO samples, two components, higher and lower-energy ones, were resolved on both Cu and Au peaks in the RBS random spectrum. For single-crystalline AlO samples, a double-peak structure was clearly observed on both Al and O surface peaks in the RBS aligned spectrum. The charge-state distribution can be obtained from the intensity of each component. The results obtained here are compared with previous data for the equilibrium charge-state distribution.
Ota, Nobuaki*; Nakagawa, Seiko*; Nishiyama, Fumitaka*; Morishita, Norio; Oshima, Takeshi
no journal, ,
A bulk with 0.5-1 mm thickness of polyaniline was irradiated by the 3MV Tandem accelerator at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) facility. ESR spectra of N or P doped polyaniline were measured at 77 K. A broad peak of polyaniline radical was observed. Except for polyaniline radical, new signals were also appeared when the fluence of doped N was less than 210ions/cm and that of P was more than 610ions/cm.
Takahiro, Katsumi*; Ninakuchi, Yuki*; Isshiki, Toshiyuki*; Nishio, Koji*; Nishiyama, Fumitaka*; Yamamoto, Shunya; Sasase, Masato*
no journal, ,
no abstracts in English
Ninakuchi, Yuki*; Saito, Masahiro*; Isshiki, Toshiyuki*; Nishio, Koji*; Nishiyama, Fumitaka*; Yamamoto, Shunya; Sasase, Masato*; Takahiro, Katsumi*
no journal, ,
In the course of Ag implantation into thermally grown SiO films, we found well-ordered Ag nanoparticles in the vicinity of SiO/Si interface. SiO films of 300 nm thick were grown on single crystalline Si(111) substrates. The SiO/Si samples were implanted with 350 keV-Ag ions to a fluence of 110 ions/cm. The Ag-implanted SiO/Si samples were characterized by Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and cross sectional transmission electron microscopy (XTEM). The Ag concentration depth profiles obtained by RBS and XPS were non-Gaussian, indicating that Ag atoms diffused significantly. XTEM revealed that well-arranged Ag nanoparticles of 30 nm and 2 nm in diameter were distributed near the projected range and the SiO/Si interface, respectively.