Miao, P.*; Tan, Z.*; Lee, S. H.*; Ishikawa, Yoshihisa*; Torii, Shuki*; Yonemura, Masao*; Koda, Akihiro*; Komatsu, Kazuki*; Machida, Shinichi*; Sano, Asami; et al.
Physical Review B, 103(9), p.094302_1 - 094302_18, 2021/03
The layered perovskite PrBaCoO demonstrates a strong negative thermal expansion (NTE) which holds potential for being fabricated into composites with zero thermal expansion. The NTE was found to be intimately associated with the spontaneous magnetic ordering, known as magneto-volume effect (MVE). Here we report with compelling evidences that the continuous-like MVE in PrBaCoO is intrinsically of discontinuous character, originating from an magnetoelectric transition from an antiferromagnetic insulating large-volume (AFILV) phase to a ferromagnetic less-insulating small-volume (FLISV) phase. Furthermore, the magnetoelectric effect (ME) shows high sensitivity to multiple external stimuli such as temperature, carrier doping, hydrostatic pressure, magnetic field etc. In contrast to the well-known ME such as colossal magnetoresistance and multi-ferroic effect which involve symmetry breaking of crystal structure, the ME in the cobaltite is purely isostructural. Our discovery provides a new path way to realizing the ME as well as the NTE, which may find applications in new techniques.
Imai, Masaki; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Onuma, Yuichi*; Maekawa, Sadamichi; Saito, Eiji
Applied Physics Letters, 114(16), p.162402_1 - 162402_4, 2019/04
Imai, Masaki; Ogata, Yudai*; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru*; Onuma, Yuichi*; Maekawa, Sadamichi; Saito, Eiji
Applied Physics Letters, 113(5), p.052402_1 - 052402_3, 2018/07
Ogata, Yudai; Chudo, Hiroyuki; Gu, B.; Kobayashi, Nobukiyo*; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Saito, Eiji; Maekawa, Sadamichi
Journal of Magnetism and Magnetic Materials, 442, p.329 - 331, 2017/11
Takahashi, Ryo*; Matsuo, Mamoru; Ono, Masao; Harii, Kazuya; Chudo, Hiroyuki; Okayasu, Satoru; Ieda, Junichi; Takahashi, Saburo*; Maekawa, Sadamichi; Saito, Eiji
Nature Physics, 12, p.52 - 56, 2016/01
Ono, Masao; Chudo, Hiroyuki; Harii, Kazuya; Okayasu, Satoru; Matsuo, Mamoru; Ieda, Junichi; Takahashi, Ryo*; Maekawa, Sadamichi; Saito, Eiji
Physical Review B, 92(17), p.174424_1 - 174424_4, 2015/11
Harii, Kazuya; Chudo, Hiroyuki; Ono, Masao; Matsuo, Mamoru; Ieda, Junichi; Okayasu, Satoru; Maekawa, Sadamichi; Saito, Eiji
Japanese Journal of Applied Physics, 54(5), p.050302_1 - 050302_3, 2015/05
Chudo, Hiroyuki; Harii, Kazuya; Matsuo, Mamoru; Ieda, Junichi; Ono, Masao; Maekawa, Sadamichi; Saito, Eiji
Journal of the Physical Society of Japan, 84(4), p.043601_1 - 043601_4, 2015/04
Ogata, Yudai*; Iguchi, Yusuke*; Tokuda, Makoto*; Januszko, K.*; Khandaker, J. I.*; Ono, Masao; Mashimo, Tsutomu*
Journal of Applied Physics, 117(12), p.125902_1 - 125902_6, 2015/03
Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru; Ieda, Junichi; Haruki, Rie*; Okayasu, Satoru; Maekawa, Sadamichi; Yasuoka, Hiroshi; Saito, Eiji
Applied Physics Express, 7(6), p.063004_1 - 063004_4, 2014/06
A magnetic field is predicted to emerge on a particle in a rotating body even if the body is electrically neutral. This emergent field is called a Barnett field. We show that nuclear magnetic resonance (NMR) enables direct measurement of the Barnett field in solids. We rotated both a sample and an NMR coil synchronously at high speed and found an NMR shift whose sing reflects that of the nuclear magnetic moments. This result provides direct evidence of the Barnett field. The use of NMR for Barnett field measurement enables the unknown signs of nuclear magnetic moments in solids to be determined.
Ono, Masao; Okayasu, Satoru; Iguchi, Yusuke*; Esaka, Fumitaka; Bagum, R.*; Haruki, Rie; Mashimo, Tsutomu*
Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan (Internet), 12(ists29), p.Tq_1 - Tq_3, 2014/04
We had realized the composition gradient of elements or isotopes in some binary alloys or single element by solid-state centrifugation. While, it might difficult to realize graded structure of elements in binary ionic crystal by centrifugation as it strongly keeps their stoichiometry. However, isotope fractionation in binary ionic crystal by centrifugation might be expected as the self-diffusion of ions occurs. We have planed the ultracentrifuge experiments on -AgI superionic conductor to investigate the isotope effect in binary ionic crystal under a strong centrifugal acceleration field. -AgI superionic conductor is suitable for the confirmation experiment as it is an intrinsic ionic crystal and Ag ions have high diffusivity. For the first stage, we have experimentally searched the experimental conditions of magnitude of centrifugal acceleration and temperature that ensure the experiment without decomposition. It is confirmed that the combination of experimental conditions of up to 6.110 g, 350C, 24h ensure the experiment without decomposition at least.
Shiraishi, Iyo; Suzuki, Masao*; Shikazono, Naoya; Fujii, Kentaro; Yokoya, Akinari
Journal of Radiation Research, 55(Suppl.1), p.i92 - i93, 2014/03
Ushigome, Takeshi*; Shikazono, Naoya; Fujii, Kentaro; Watanabe, Ritsuko; Suzuki, Masao*; Tsuruoka, Chizuru*; Tauchi, Hiroshi*; Yokoya, Akinari
Radiation Research, 177(5), p.614 - 627, 2012/05
The yield of DNA damage produced in fully hydrated plasmid DNA films has been investigated to determine the linear energy transfer (LET) dependence of damage induction. The yield of single strand breaks (SSBs) with increasing LET levels of He, C and Ne ions. On the other hand, the yields of prompt double strand breaks (DSBs) increased with increasing LET. SSBs were additionally induced by treatment with base excision repair proteins, glycosylases, indicating that base lesions are produced in the hydrated DNA. This result shows that nucleobase lesions are produced via both chemical reactions with diffusible water radicals and direct energy deposition onto DNA or the hydrated layer. The yield of SSBs or DSBs observed by enzymatic treatment notably decreased with increasing LET. These results indicated that higher LET ions preferentially produce a complex type of damage that might compromise the activities of the proteins used in this study.
Okayasu, Satoru; Ono, Masao; Nishio, Taichiro*; Iguchi, Yusuke*; Mashimo, Tsutomu*
Defect and Diffusion Forum, 323-325, p.545 - 548, 2012/04
Atomic sedimentation in solid occurs under mega-gravity treatment. As the result, partially melt-growth in -phase of BiPb-alloy occurs. Small difference of densities between fully hcp structure of BiPb and that of partially defected BiPb are enhanced under mega-gravity, and cause the separation of the -phase. Superconducting properties differs between the separated two phases.
Ono, Masao; Okayasu, Satoru; Esaka, Fumitaka; Haruki, Rie; Mashimo, Tsutomu*
Journal of the Japan Society of Microgravity Application, 28(2), p.S89 - S91, 2011/04
An ultracentrifuge experiment was performed on a pure liquid-indium at acceleration field of 8.210 g at 300C for 100 hours. The isotope ratio measurements were performed on the centrifuged specimen with Secondary Ion Mass Spectrometer (CAMECA IMS-6f). In/In isotope ratio on the specimen changed with negative gradient in the direction of centrifugal force approximately 1.3%. The measurement result indicated that the heavy In isotopes moved in the direction of the centrifugal force and the light In isotopes moved in the counter direction in the specimen. At the session, we will present both the result and an approach to find a precondition to develop an isotope separation process using the phenomenon.
Iguchi, Yusuke*; Mashimo, Tsutomu*; Ono, Masao; Okayasu, Satoru
Philosophical Magazine Letters, 90(7), p.513 - 518, 2010/07
We performed an ultracentrifuge experiment on Bi-Sb alloy. Deformation twins with misorientations of about 90 were observed in the low-gravitational region where grain refinement had not occurred. The twins were thicker than the conventional deformation twins and their thickness was proportional to the gravitational field. We found that the minimum gravitational field required for grain refinement was 1.710 G at 240 C for periods 10 h.
Hao, T.; Ono, Masao; Okayasu, Satoru; Sakai, Seiji; Narumi, Kazumasa; Hiraiwa, Yusuke*; Naramoto, Hiroshi*; Maeda, Yoshihito
Nuclear Instruments and Methods in Physics Research B, 268(11-12), p.1867 - 1870, 2010/06
Takahashi, Ryuta; Ishii, Tetsuro; Asai, Masato; Nagae, Daisuke*; Makii, Hiroyuki; Tsukada, Kazuaki; Toyoshima, Atsushi; Ishii, Yasuo; Matsuda, Makoto; Makishima, Akiyasu*; et al.
Physical Review C, 81(5), p.057303_1 - 057303_4, 2010/05
The ground-state bands of Cf have been established up to 10, 12, and 10 states, respectively, by in-beam -ray spectroscopy using neutron-transfer reactions with a O beam and a highly radioactive Cf target. The deexcitation rays in Cf were identified by taking coincidences with outgoing particles of O measured with Si - detectors, and by selecting their kinetic energies. This is the first in-beam -ray spectroscopy for Cf isotopes.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.