High-rate crystallization of polycarbonate in spincast thin film

Ata, Seisuke*; Oka, Toshitaka; He, C.-Q.*; Odaira, Toshiyuki*; Suzuki, Ryoichi*; Ito, Kenji*; Kobayashi, Yoshinori*; Ougizawa, Toshiaki*

Journal of Polymer Science, Part B; Polymer Physics, 48(20), p.2148 - 2153, 2010/10

https://doi.org/10.1002/polb.22096

Surface morphology of bisphenol-A polycarbonate (BAPC) thin films with thickness ranging from 30 to 1000 nm on silicon substrates was studied by atomic force microscopy (AFM). The films were prepared by spincasting from 1,2-dichloroethane solutions of 0.25-5.0 wt % BAPC. Even though longer annealing than 250 h was necessary for complete crystallization for bulk BAPC, high crystallinity was observed for 30 nm thick film after annealing at 200 C for 48 h in vacuum. Positron annihilation lifetime spectroscopy (PALS) measurements showed that the free volume hole size in 30 nm thick film was larger than that of bulk at 200 C. Comparison of the BAPC concentration in the precursor solution with the overlap concentration suggests that the high crystallinity of the 30 nm BAPC film is due to less entangled chains caused by rapid removal of the solvent from the dilute solution.

Progress in R&D efforts on the energy recovery linac in Japan

Sakanaka, Shogo*; Ago, Tomonori*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; Harada, Kentaro*; Hiramatsu, Shigenori*; Honda, Toru*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.205 - 207, 2008/06

Future synchrotron light sources based on the energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. Our Japanese collaboration team is making efforts for realizing an ERL-based hard X-ray source. We report recent progress in our R&D efforts.

Crystallization of an amorphous layer in P-implanted 6H-SiC studied by monoenergetic positron beams

Uedono, Akira*; Tanigawa, Shoichiro*; Oshima, Takeshi; Ito, Hisayoshi; Yoshikawa, Masahito; Nashiyama, Isamu; Frank, T.*; Pensl, G.*; Suzuki, Ryoichi*; Odaira, Toshiyuki*; et al.

Journal of Applied Physics, 87(9), p.4119 - 4125, 2000/05

https://doi.org/10.1063/1.373039

no abstracts in English

Investigation of positron moderator materials for electron-linac-based slow positron beamlines

Suzuki, Ryoichi*; *; Uedono, Akira*; Y.K.Cho*; Yoshida, Sadafumi*; Ishida, Yuki*; Oshima, Takeshi; Ito, Hisayoshi; *; Mikado, Tomohisa*; et al.

Japanese Journal of Applied Physics, Part 1, 37(8), p.4636 - 4643, 1998/08

https://doi.org/10.1143/JJAP.37.4636

no abstracts in English

Study of thermal annealing of vacancies in ion implanted 3C-SiC by positron annihilation

Oshima, Takeshi; Uedono, Akira*; Ito, Hisayoshi; Abe, Koji*; Suzuki, Ryoichi*; *; Aoki, Yasushi; Tanigawa, Shoichiro*; Yoshikawa, Masahito; Mikado, Tomohisa*; et al.

Mater. Sci. Forum, 264-268, p.745 - 748, 1998/00

no abstracts in English

Design of High Temperature Engineering Test Reactor (HTTR)

Saito, Shinzo; Tanaka, Toshiyuki; Sudo, Yukio; Baba, Osamu; Shindo, Masami; Shiozawa, Shusaku; Mogi, Haruyoshi; Okubo, Minoru; Ito, Noboru; Shindo, Ryuichi; et al.

JAERI 1332, 247 Pages, 1994/09

JAERI-1332.pdf:11.53MB

no abstracts in English

Investigation of the near surface damage layer induced by electric discharge machining in steel

Jiang, L.*; O'Rourke, B. E.*; Harada, Yoshihisa*; Takatsu, Shuhei*; Ito, Kenji*; Okubo, Masataka*; Hirade, Tetsuya; Uedono, Akira*; Suzuki, Ryoichi*; Takai, Kenichi*; et al.

no journal, , 

We are studying the depth dependence of the density of the defects induced by the electrical discharge machining (EDM) in SUS316L, using the electron probe microanalysis (EPMA), Positron annihilation lifetime spectroscopy (PALS) and X-ray diffraction (XRD). EPMA results show a large change in the composition over the first 10 m. This layer can be assumed to correspond to the recast layer. PALS and XRD results suggest a defect layer with a thickness of around 50 m. This depth can be assumed to correspond to the heat affected zone where dislocations and vacancy clusters exists. For PALS (and other methods) analysis, it is recommended to remove the topmost 100 m of the samples by chemical polishing after EDM.