Extreme phonon anharmonicity underpins superionic diffusion and ultralow thermal conductivity in argyrodite AgSnSe

Ren, Q.*; Gupta, M. K.*; Jin, M.*; Ding, J.*; Wu, J.*; Chen, Z.*; Lin, S.*; Fabelo, O.*; Rodriguez-Velamazan, J. A.*; Kofu, Maiko; et al.

Nature Materials, 22, p.999 - 1006, 2023/05

https://doi.org/10.1038/s41563-023-01560-x

Aerosol experiments and measurement techniques on pool scrubbing-related source term issues

Lebel, L. S.*; Morreale, A. C.*; Freitag, M.*; Gupta, S.*; Allelein, H.-J.*; Klauck, M.*; Sun, Haomin; Herranz, L. E.*

Proceedings of 19th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-19) (Internet), 16 Pages, 2022/03

Correlation of anomalous Hall effect with structural parameters and magnetic ordering in MnSn thin films

Yoon, J.-Y.*; Takeuchi, Yutaro*; DuttaGupta, S.*; Yamane, Yuta*; Kanai, Shun*; Ieda, Junichi; Ohno, Hideo*; Fukami, Shunsuke*

AIP Advances (Internet), 11(6), p.065318_1 - 065318_6, 2021/06

https://doi.org/10.1063/5.0043192

Fusion reaction Ca+Bk leading to formation of the element Ts (Z=117)

Khuyagbaatar, J.*; Yakushev, A.*; Dllmann, Ch. E.*; Ackermann, D.*; Andersson, L.-L.*; Asai, Masato; Block, M.*; Boll, R. A.*; Brand, H.*; Cox, D. M.*; et al.

Physical Review C, 99(5), p.054306_1 - 054306_16, 2019/05

AA2019-0039.pdf:5.03MB

https://doi.org/10.1103/PhysRevC.99.054306

We have performed an experiment to synthesize the element 117 (Ts) with the Ca+Bk fusion reaction. Four -decay chains attributed to the element 117 were observed. Two of them were long decay chains which can be assigned to the one originating from the decay of Ts. The other two were short decay chains which are consistent with the one originating from the decay of Ts. We have compared the present results with the literature data, and found that our present results mostly confirmed the literature data, leading to the firm confirmation of the synthesis of the element 117.

Comparison of heavy-ion transport simulations; Collision integral in a box

Zhang, Y.-X.*; Wang, Y,-J.*; Colonna, M.*; Danielewicz, P.*; Ono, Akira*; Tsang, M. B.*; Wolter, H.*; Xu, J.*; Chen, L.-W.*; Cozma, D.*; et al.

Physical Review C, 97(3), p.034625_1 - 034625_20, 2018/03

https://doi.org/10.1103/PhysRevC.97.034625

International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and 320 neutrons were packed in a 20-fm-large cube to calculate the number of particle-particle collisions as well as the energies of collisions during the time evolution. In addition to the calculation, their algorithms were compared. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). The results were compared with those calculated by the other 15 codes from over the world. Algorithm comparison showed that JQMD calculates collision probabilities from protons at first and collisions by neutrons are simulated later, which might be unreasonable. On the other hand, it was clarified that the calculation by JQMD agrees with those by the others. Despite the fact that some codes deviate from the average by a factor of 2, JQMD exhibited stable performance.

Valence-band electronic structure evolution of graphene oxide upon thermal annealing for optoelectronics

Yamaguchi, Hisato*; Ogawa, Shuichi*; Watanabe, Daiki*; Hozumi, Hideaki*; Gao, Y.*; Eda, Goki*; Mattevi, C.*; Fujita, Takeshi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; et al.

Physica Status Solidi (A), 213(9), p.2380 - 2386, 2016/09

https://doi.org/10.1002/pssa.201532855

We report valence-band electronic structure evolution of graphene oxide (GO) upon its thermal reduction. The degree of oxygen functionalization was controlled by annealing temperature, and an electronic structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in the density of states around the Fermi level upon thermal annealing at 600C. The result indicates that while there is an apparent bandgap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of bandgap closure was correlated with the electrical, chemical, and structural properties to determine a set of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of 500C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to an as-synthesized counterpart.

Development of a new continuous dissolution apparatus with a hydrophobic membrane for superheavy element chemistry

Oe, Kazuhiro*; Attallah, M. F.*; Asai, Masato; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Huang, M.*; Kanaya, Jumpei*; Kaneya, Yusuke*; Kasamatsu, Yoshitaka*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1317 - 1320, 2015/02

https://doi.org/10.1007/s10967-014-3469-3

A new technique for continuous dissolution of nuclear reaction products transported by a gas-jet system was developed for superheavy element (SHE) chemistry. In this technique, a hydrophobic membrane is utilized to separate an aqueous phase from the gas phase. With this technique, the dissolution efficiencies of short-lived radionuclides of Mo and W were measured. Yields of more than 80% were observed for short-lived radionuclides at aqueous-phase flow rates of 0.1-0.4 mL/s. The gas flow-rate had no influence on the dissolution efficiency within the studied flow range of 1.0-2.0 L/min. These results show that this technique is applicable for on-line chemical studies of SHEs in the liquid phase.

Quantitative study of the spin Hall magnetoresistance in ferromagnetic insulator/normal metal hybrids

Althammer, M.*; Meyer, S.*; Nakayama, Hiroyasu*; Schreier, M.*; Altmannshofer, S.*; Weiler, M.*; Huebl, H.*; Geprgs, S.*; Opel, M.*; Gross, R.*; et al.

Physical Review B, 87(22), p.224401_1 - 224401_15, 2013/06

https://doi.org/10.1103/PhysRevB.87.224401

We experimentally investigate and quantitatively analyze the spin Hall magnetoresistance (SMR) effect in ferromagnetic insulator (FI)/Pt and FI/nonmagnetic metal/Pt hybrid structures. For the FI, we use either YIG, nickel ferrite, or magnetite and for the nonmagnet, Cu or Au. The SMR is theoretically ascribed to the combined action of spin Hall and inverse spin Hall effect in the Pt top layer. It therefore should characteristically depend upon the orientation of the magnetization in the adjacent ferromagnet and prevail even if an additional, nonmagnetic metal layer is inserted between Pt and the ferromagnet. Our experimental data corroborate these theoretical conjectures. Using the SMR theory to analyze our data, we extract the spin Hall angle and the spin diffusion length in Pt. For a spin-mixing conductance of m, we obtain a spin Hall angle of 0.11 0.08 and a spin diffusion length of (1.5 0.5) nm for Pt in our samples.

Hybridization between the conduction band and 3 orbitals in the oxide-based diluted magnetic semiconductor InVO

Kobayashi, Masaki*; Ishida, Yukiaki*; Hwang, J. I.*; Song, G. S.*; Takizawa, Masaru*; Fujimori, Atsushi; Takeda, Yukiharu; Okochi, Takuo*; Okane, Tetsuo; Saito, Yuji; et al.

Physical Review B, 79(20), p.205203_1 - 205203_5, 2009/05

https://doi.org/10.1103/PhysRevB.79.205203

Experimental progress on zonal flow physics in toroidal plasmas

Fujisawa, Akihide*; Ido, Takeshi*; Shimizu, Akihiro*; Okamura, Shoichi*; Matsuoka, Keisuke*; Hamada, Yasuji*; Hoshino, Katsumichi; Nagashima, Yoshihiko*; Shinohara, Koji; Nakano, Haruhisa*; et al.

Proceedings of 21st IAEA Fusion Energy Conference (FEC 2006) (CD-ROM), 12 Pages, 2007/03

http://www-naweb.iaea.org/napc/physics/FEC/FEC2006/html/node104.htm#26311

Present status of experiments on zonal flows is overviewed. Innovative use of traditional and modern diagnostics has revealed unambiguously the existense of the zonal flows, their spatio-temporal caracteristics, their relationship with turbulence, and their effects on confinement. Particularly, a number of observations have been accumulated on the oscillatory branch of zonal flows, dubbed geodesic acoustic modes, suggesting necessity of theories to give their proper description. Furthur investigation of relationship between zonal flows and confinement is strongly encouraged as cross-device activity.