JAEA
  • help
  • PC | SP
  • JP | EN
          
Refine your search：     
Report No.
 - 
Clear All
Search Results: Records 1-3 displayed on this page of 3
  • 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

Oral presentation

Small-angle neutron scattering measurements of Neodymium-Iron-Boron (Nd-Fe-B) sintered magnets

Takeda, Masayasu; Suzuki, Junichi; Yamaguchi, Daisuke; Akiya, Takahiro*; Kato, Hiroaki*; Une, Yasuhiro*; Sagawa, Masato*

no journal, , 

A Neodymium Iron Boron (Nd-Fe-B) sintered magnet is the most powerful permanent magnet among the commercially available ones. Because of the low $$T_{c}$$, the coercivity of this magnet rapidly reduces above the room temperature. It is well known that substitution of dysprosium (Dy) for a part of Nd recovers the coercivity at the high temperatures. There are two key parameters to enhance the coercivity of Nd-Fe-B sintered magnets without the addition of Dy: grain refinement of microstructure in the magnets, and the microstructural control at the interface between Nd$$_{2}$$Fe$$_{14}$$B and Nd-rich phases surrounding the main phase. Small-angle neutron scattering (SANS) is very powerful tool to investigate such internal structures. We performed SANS measurements of the Nd-Fe-B sintered magnets using unpolarized and polarized neutrons on SANS-J-II installed at JRR-3. The information is essential to the achievement of the high-coercivity Dy-free Nd-Fe-B sintered magnet.

Oral presentation

Formation of liquid crystalline phases in colloidal suspensions of K$$_{4}$$Nb$$_{6}$$O$$_{17}$$ nanosheet

Yamaguchi, Daisuke; Miyamoto, Nobuyoshi*; Koizumi, Satoshi; Nakato, Teruyuki*; Yagi, Naoto*; Hashimoto, Takeji

no journal, , 

Two new experimental evidences were obtained in lyotropic liquid crystalline (LC) phase behavior consisting of a model charged colloidal platelike particle system yielded from layered niobate crystal of K$$_{4}$$Nb$$_{6}$$O$$_{17}$$. Firstly, the effect of mean lateral size ($$overline{D}$$$$_{lat}$$) of the particle was examined at a constant volume fraction of the particle ($$phi$$) where a LC phase coexisted with an isotropic (I) phase. The coexisting LC phase was abruptly transformed from nematic to lamellar (L) as $$overline{D}$$$$_{lat}$$ was decreased. Secondly, the $$phi$$ dependence of the interparticle distance (d) was examined along the I-L transition. In the coexistence region, d showed nearly the same value between those two phases and varied with $$phi$$, being out of the usual lever rule.

Oral presentation

A Combined method of small-angle neutron scattering and neutron radiography to visualize water in operating fuel cell over a wide length scale from nano to millimeter

Koizumi, Satoshi; Yamaguchi, Daisuke; Iwase, Hiroki*; Putra, A.; Maekawa, Yasunari; Matsubayashi, Masahito; Hashimoto, Takeji

no journal, , 

In order to visualize water generated in an operating polymer electrolyte fuel cell (PEFC), a neutron radiography (NR) apparatus, composed of a scintillator, optical mirrors and a CCD camera, was installed at a sample position of the focusing and polarized neutron small-angle scattering (SANS) spectrometer (SANS-J-II) at research reactor JRR-3. By combining SANS and NR, we aim to cover a wide length scale from nanometer to millimeter. The new method succeeded in detecting a spatial distribution of the water generated in individual cell elements; NR detected the water in a gas diffusion layer and a flow-field, whereas SANS quantitatively determines the water content in a membrane electrode assembly (MEA).

3 (Records 1-3 displayed on this page)
  • 1