Chirality memory stored in magnetic domain walls in the ferromagnetic state of MnP

Jiang, N.*; Nii, Yoichi*; Arisawa, Hiroki*; Saito, Eiji; Oe, Junichiro*; Onose, Yoshinori*

Physical Review Letters, 126(17), p.177205_1 - 177205_5, 2021/04

https://doi.org/10.1103/PhysRevLett.126.177205

Effect of spin dilution on the magnetic state of delafossite CuCrO with an = 3/2 antiferromagnetic triangular sublattice

Okuda, Tetsuji*; Uto, Kazuma*; Seki, Shinichiro*; Onose, Yoshinori*; Tokura, Yoshinori*; Kajimoto, Ryoichi; Matsuda, Masaaki*

Journal of the Physical Society of Japan, 80(1), p.014711_1 - 014711_7, 2011/04

https://doi.org/10.1143/JPSJ.80.014711

Nematic-to-smectic transition of magnetic texture in conical state

Takeda, Masayasu; Endo, Yasuo; Kakurai, Kazuhisa; Onose, Yoshinori*; Suzuki, Junichi; Tokura, Yoshinori*

Journal of the Physical Society of Japan, 78(9), p.093704_1 - 093704_4, 2009/09

https://doi.org/10.1143/JPSJ.78.093704

The complex phase transition of the magnetic long-range order in FeCoSi has been investigated by small-angle neutron scattering (SANS) measurement at low temperatures under an external magnetic field. A variety of scattering patterns, such as ring, crescent-shaped, and diffusive spots, were observed by changing temperature and applying a magnetic field. The results could be interpreted by an analogy of the phase transition of the liquid crystal when the net magnetization is regarded as the director of the liquid crystal.

Irradiation behavior of the BC neutron absorber materials; Results of the JOYO AMIR irradiation experiments

Kimura, Yoshio; Kaito, Takeji; Onose, Shoji; Sato, Yoshinori; Shibahara, Itaru

PNC TN9410 91-171, 17 Pages, 1991/04

PNC-TN9410-91-171.pdf:0.66MB

The BC neutron absorber material has great advantage of high neutron absorbing capability, although the He release and the swelling limit the life time of control rod. So it is important for the life time extension and reliability improvement to investigate the irradiation behavior of the BC. This report discuss the important parameters which may control the absorber pin behavior based on the irradiation test results obtained recently by the JOYO AMIR experiments, and re-evaluate the current technical issues and the way of improvements. The He release from BC pellet increase rapidly after a burnup of 10010 cap/cm and exceed the value predicted by the equation which has been applied to the MONJU design. The data is still required when we adopt the seal type absorber pin to use at high burnup. The He release found to depend on the B enrichment as well as the grain size. The He release could be reduced by the optimization of these parameters although the swelling behavior should also be considered since the swelling generally increases with decreasing the He release. The absorber cladding mechanical interaction (ACMI) is accelerated due to pellet cracking and relocation and essentially limits the life time of control rod. The relocation becomes generally extensive as the pellet-to-cladding gap is increased, but this behavior consider to be stochastic and difficult to make quantitative prediction. Improvement could be attained by using a shroud type absorber pin. Reduction of thermal conductivity during irradiation is considered to be caused by micro-defects including the micro-cracking. The degradation may be improved by introducing BC cermet.

Correlation between the long-range magnetic order and the magnetic domain structure in FeCoSi during the magnetization process

Takeda, Masayasu; Endo, Yasuo; Onose, Yoshinori*; Kakurai, Kazuhisa; Suzuki, Junichi; Tokura, Yoshinori*

no journal, , 

A ferromagnetic metal, FeCoSi (), has a long-period helical spin structure due to the Dzyalosinsky-Moriya interaction. The Chirality of the helical structure decides either clockwise or anti-clockwise because the cubic B20 structure lacks the inversion center. We conclude that a new magnetic phase (a magnetic liquid crystal phase) exists in FeCoSi under the external magnetic fields judging from the detailed magnetization process determined by polarized neutron small angle scattering measurements.