Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 20
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Nonmagnetic-magnetic transition and magnetically ordered structure in SmS

Yoshida, Shogo*; Koyama, Takehide*; Yamada, Haruhiko*; Nakai, Yusuke*; Ueda, Koichi*; Mito, Takeshi*; Kitagawa, Kentaro*; Haga, Yoshinori

Physical Review B, 103(15), p.155153_1 - 155153_5, 2021/04

 Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)

Journal Articles

Surface analysis of single-crystalline $$beta$$-FeSi$$_2$$

Yamada, Yoichi*; Mao, W.*; Asaoka, Hidehito; Yamamoto, Hiroyuki; Esaka, Fumitaka; Udono, Haruhiko*; Tsuru, Tomohito

Physics Procedia, 11, p.67 - 70, 2011/02

 Times Cited Count:3 Percentile:84.58

Clean surfaces of the single crystalline $$beta$$-FeSi$$_2$$ have been prepared and investigated. From XPS (X-ray Photoelectron Spectroscopy) measurements of the surface oxide, it is found that the surface Si is mainly oxidized while Fe isn't. After removing the surface oxide, clean surface can be obtained showing reasonable structure in LEED (Low-Energy Electron Diffraction) and STM (Scanning Tunneling Microscope). No drastic surface reconstruction is found reflecting strong Fe-Si bond. DFT (Density Functional Theory) calculation suggests the spin polarized surface DOS (Density Of State) when Fe comes at the surface.

Journal Articles

Surface preparation and characterization of single crystalline $$beta$$-FeSi$$_{2}$$

Yamada, Yoichi; Wakaya, Ippei*; Ouchi, Shinji*; Yamamoto, Hiroyuki; Asaoka, Hidehito; Shamoto, Shinichi; Udono, Haruhiko*

Surface Science, 602(18), p.3006 - 3009, 2008/09

 Times Cited Count:6 Percentile:31.88(Chemistry, Physical)

Well-defined clean surfaces of single crystalline $$beta$$-FeSi$$_{2}$$ have for the first time been prepared and characterized at the atomic scale. Surface oxide was removed by heating the crystal at 850 $$^{circ}$$C in ultra-high vacuum (UHV), resulted in an atomically-flat, clean surface. Scanning tunneling microscope (STM) and low-energy electron diffraction (LEED) measurements reveal the absence of long-range surface reconstruction in the low-index (100), (101) and (110) surfaces, which is unique among compound semiconductors. However a significant number of surface defects could still be found within the clean surface. Characterizing and controlling of those surface defects will be necessary in order to use this material in applications.

Journal Articles

Local neutron transmutation doping using isotopically enriched silicon film

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Yamaguchi, Kenji; Udono, Haruhiko*; Shamoto, Shinichi; Yokoyama, Atsushi; Hojo, Kiichi

Journal of Physics and Chemistry of Solids, 68(11), p.2204 - 2208, 2007/11

 Times Cited Count:6 Percentile:33.03(Chemistry, Multidisciplinary)

$$^{30}$$Si in natural Si has been widely used for a doping source, since $$^{30}$$Si can be transmuted into $$^{31}$$P by thermal neutron (Neutron Transmutation Doping, NTD). NTD of nanostructure fabricated from $$^{30}$$Si-enriched materials can serve as a controlled local doping method with tunable dopant concentration, which cannot be realized by conventional doping methods such as ion implantation. In the present study, $$^{30}$$Si-enriched thin film has been fabricated in order to demonstrate the local NTD. The $$^{30}$$Si-enriched film with thickness of 100 nm was deposited on the Si(100) substrate by plasma enhanced chemical vapor deposition using $$^{30}$$Si-enriched SiF$$_{4}$$ as the source gases. The film contains 7.1 % of $$^{30}$$Si, which is twice higher than that of natural Si. Possible contaminant, fluorine, is lower than 0.6 at.% determined from X-ray photoelectron spectra. Nanostructure of films and changes of electronic properties by the neutron irradiation will also be discussed.

Journal Articles

In-situ tritium recovery behavior from Li$$_{2}$$TiO$$_{3}$$ pebble bed under neutron pulse operation

Tsuchiya, Kunihiko; Kikukawa, Akihiro*; Hoshino, Tsuyoshi; Nakamichi, Masaru; Yamada, Hirokazu*; Yamaki, Daiju; Enoeda, Mikio; Ishitsuka, Etsuo; Kawamura, Hiroshi; Ito, Haruhiko; et al.

Journal of Nuclear Materials, 329-333(Part2), p.1248 - 1251, 2004/08

 Times Cited Count:10 Percentile:58.07(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Preliminary neutronic estimation for demo blanket with beryllide

Yamada, Hirokazu*; Nagao, Yoshiharu; Kawamura, Hiroshi; Nakao, Makoto*; Uchida, Munenori*; Ito, Haruhiko

Fusion Engineering and Design, 69(1-4), p.269 - 273, 2003/09

 Times Cited Count:13 Percentile:66.42(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Evaluation of effective thermal diffusivity of Li$$_2$$TiO$$_3$$ pebble bed under neutron irradiation

Kawamura, Hiroshi; Kikukawa, Akihiro*; Tsuchiya, Kunihiko; Yamada, Hirokazu*; Nakamichi, Masaru; Ishitsuka, Etsuo; Enoeda, Mikio; Ito, Haruhiko

Fusion Engineering and Design, 69(1-4), p.263 - 267, 2003/09

 Times Cited Count:3 Percentile:26.72(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Development of advanced blanket materials for a solid breeder blanket of a fusion reactor

Kawamura, Hiroshi; Ishitsuka, Etsuo; Tsuchiya, Kunihiko; Nakamichi, Masaru; Uchida, Munenori*; Yamada, Hirokazu*; Nakamura, Kazuyuki; Ito, Haruhiko; Nakazawa, Tetsuya; Takahashi, Heishichiro*; et al.

Nuclear Fusion, 43(8), p.675 - 680, 2003/08

 Times Cited Count:26 Percentile:63.92(Physics, Fluids & Plasmas)

no abstracts in English

Oral presentation

Fabrication of $$^{30}$$Si-enriched thin film for local neutron transmutation doping

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Yamaguchi, Kenji; Udono, Haruhiko*; Shamoto, Shinichi; Yokoyama, Atsushi; Hojo, Kiichi

no journal, , 

$$^{30}$$Si in natural Si has been widely used for a doping source, since $$^{30}$$Si can be transmuted into $$^{31}$$P by thermal neutron (Neutron Transmutation Doping, NTD). NTD of nanostructure fabricated from $$^{30}$$Si-enriched materials can serve as a controlled local doping method with tunable dopant concentration, which cannot be realized by conventional doping methods such as ion implantation. In the present study, $$^{30}$$Si-enriched thin film has been fabricated in order to demonstrate the local NTD. The $$^{30}$$Si-enriched film with thickness of 100 nm was deposited on the Si(100) substrate by plasma enhanced chemical vapor deposition using $$^{30}$$Si-enriched SiF$$_{4}$$ as the source gases. The film contains 7.1 % of $$^{30}$$Si, which is twice higher than that of natural Si. Possible contaminant, fluorine, is lower than 0.6 at.% determined from X-ray photoelectron spectra. Nanostructure of films and changes of electronic properties by the neutron irradiation will also be discussed.

Oral presentation

$$^{30}$$Si-enriched thin film for local neutron transmutation doping

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Yamaguchi, Kenji; Udono, Haruhiko*; Shamoto, Shinichi; Yokoyama, Atsushi; Hojo, Kiichi

no journal, , 

$$^{30}$$Si in natural Si has been widely used for a doping source, since $$^{30}$$Si can be transmuted into $$^{31}$$P by thermal neutron (Neutron Transmutation Doping, NTD). In the present study, $$^{30}$$Si-enriched thin film has been fabricated in order to demonstrate the local NTD. The $$^{30}$$Si-enriched film with thickness of 100 nm was deposited on the Si(100) substrate by plasma enhanced chemical vapor deposition using $$^{30}$$Si-enriched SiF$$_{4}$$ as the source gases. Nanostructure of films and changes of electronic properties by the neutron irradiation will be discussed.

Oral presentation

$$^{30}$$Si-enriched thin film for local neutron transmutation doping

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Yamaguchi, Kenji; Udono, Haruhiko*; Shamoto, Shinichi; Yokoyama, Atsushi; Hojo, Kiichi

no journal, , 

$$^{30}$$Si in natural Si has been widely used for a doping source, since $$^{30}$$Si can be transmuted into $$^{31}$$P by thermal neutron (Neutron Transmutation Doping, NTD). In the present study, $$^{30}$$Si-enriched thin film has been fabricated in order to demonstrate the local NTD. The $$^{30}$$Si-enriched film with thickness of 100 nm was deposited on the Si(100) substrate by plasma enhanced chemical vapor deposition using $$^{30}$$Si-enriched SiF$$_{4}$$ as the source gases. Nanostructure of films and changes of electronic properties by the neutron irradiation will be discussed.

Oral presentation

Thermal preannealing of single crystalline $$beta$$-FeSi$$_{2}$$ substrate for MBE

Ouchi, Shinji*; Muroga, Masataka*; Udono, Haruhiko*; Yamada, Yoichi; Yamamoto, Hiroyuki; Kikuma, Isao*

no journal, , 

Thermal preannealing of single crystalline $$beta$$-FeSi$$_{2}$$ substrate for MBE has been investigated to obtain better substrate for homo-epitaxial growth of $$beta$$-FeSi$$_{2}$$ film.

Oral presentation

RHEED observation of surface on $$beta$$-FeSi$$_{2}$$ single crystals

Wakaya, Ippei*; Muroga, Masataka*; Ouchi, Shinji*; Udono, Haruhiko*; Yamada, Yoichi; Yamamoto, Hiroyuki; Kikuma, Isao*

no journal, , 

RHEED observation of surface has been performed on $$beta$$-FeSi$$_{2}$$ single crystals.

Oral presentation

Fabrication and estimation of $$^{30}$$Si-enriched thin films for local neutron transmutation doping

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Yamaguchi, Kenji; Udono, Haruhiko*; Shamoto, Shinichi; Yokoyama, Atsushi; Hojo, Kiichi

no journal, , 

Fabrication and estimation of $$^{30}$$Si-enriched thin films for local neutron transmutation doping has been attempted.

Oral presentation

Neutron transmutation doping of $$^{30}$$Si enriched thin film

Yamada, Yoichi; Yamamoto, Hiroyuki; Oba, Hironori; Sasase, Masato*; Esaka, Fumitaka; Udono, Haruhiko*; Yamaguchi, Kenji; Yokoyama, Atsushi; Hojo, Kiichi; Shamoto, Shinichi

no journal, , 

Neutron transmutation doping has been tried by using $$^{30}$$Si enriched thin film in order to fabricate nano doping devices.

Oral presentation

Preparation and characterization of clean surface of $$beta$$-FeSi$$_{2}$$ single crystal

Yamada, Yoichi; Wakaya, Ippei*; Ouchi, Shinji*; Yamamoto, Hiroyuki; Udono, Haruhiko*

no journal, , 

Preparation method of well defined $$beta$$-FeSi$$_{2}$$(110) single crystal surface has been investigated.

Oral presentation

Homoepitaxy of $$beta$$-FeSi$$_{2}$$ thin films on various oriented substrates by MBE

Ouchi, Shinji*; Wakaya, Ippei*; Udono, Haruhiko*; Yamada, Yoichi; Yamamoto, Hiroyuki; Esaka, Fumitaka

no journal, , 

Homoepitaxial formation of $$beta$$-FeSi$$_{2}$$ thin films on various oriented substrates has been discussed.

Oral presentation

Surface analysis on single-crystalline $$beta$$-FeSi$$_{2}$$

Mao, W.; Wakaya, Ippei*; Yamada, Yoichi; Esaka, Fumitaka; Yamamoto, Hiroyuki; Shamoto, Shinichi; Yamaguchi, Kenji; Udono, Haruhiko*

no journal, , 

Thin films of semiconducting $$beta$$-FeSi$$_{2}$$ keep attracting considerable attentions for their promising applicability to the Si-based optoelectronics devices. Recently, large single-crystalline $$beta$$-FeSi$$_{2}$$ has successfully been synthesized, providing a substrate for a well-defined homoepitaxy film. As a first step toward good homoepitaxy of $$beta$$-FeSi$$_{2}$$, we prepare and characterize low-index surfaces of $$beta$$-FeSi$$_{2}$$ single crystal. Both LEED and STM reveal the absence of the long-ranged surface reconstruction for each face, which is favorable for the homoepitaxy on this substrate. On the other hand, STM suggests a presence of a significant amount of surface defects for each face, which should be improved in the next step. In addition to structural analysis, the stoichiometry of clean surfaces will be discussed on the basis of XPS and SIMS measurements.

Oral presentation

Investigation of deposit condition in the first stage of $$beta$$-FeSi$$_{2}$$ homoepitaxial growth

Wakaya, Ippei*; Ochiai, Kunihito*; Udono, Haruhiko*; Nagano, Takatoshi*; Yamada, Yoichi; Yamamoto, Hiroyuki; Esaka, Fumitaka

no journal, , 

Deposit condition in the first stage of $$beta$$-FeSi$$_{2}$$ homoepitaxial growth has been investigated.

Oral presentation

Surface observation of single crystalline $$beta$$-$${rm FeSi_2}$$

Yamada, Yoichi*; Wakaya, Ippei*; Ouchi, Shinji*; Udono, Haruhiko*; Tsuru, Tomohito; Esaka, Fumitaka; Yamamoto, Hiroyuki

no journal, , 

no abstracts in English

20 (Records 1-20 displayed on this page)
  • 1