Inelastic neutron scattering study of magnon excitation by ultrasound injection in yttrium iron garnet

Shamoto, Shinichi; Akatsu, Mitsuhiro*; Chang, L.-J.*; Nemoto, Yuichi*; Ieda, Junichi

Applied Physics Letters, 124(11), p.112402_1 - 112402_5, 2024/03

https://doi.org/10.1063/5.0189768

The magnon excitation by ultrasound injection in YFeO is studied by inelastic neutron scattering. Both longitudinal and transverse ultrasound injections enhanced the inelastic neutron scattering intensity.

Elucidation of solid particle interfacial phenomena in liquid sodium; Magnetic interactions on liquid metal and solid atoms at the solid interface

Tei, C.; Otaka, Masahiko; Kuwahara, Daisuke*

Chemical Physics Letters, 829, p.140755_1 - 140755_6, 2023/10

https://doi.org/10.1016/j.cplett.2023.140755

We were able to detect the nuclear magnetic resonance (NMR) signal of a liquid sodium clinging to the interface of solid metal particles for the first time. In this study, we confirmed the difference in the relaxation times due to the difference in the interactions between liquid sodium and metal particles suspended in the liquid sodium. It was found that the surface of the micro titanium particles and liquid metallic sodium interact physically, not chemically.

neutron diffraction study on the deformation behavior of the plastic inorganic semiconductor AgS

Wang, Y.*; Gong, W.; Kawasaki, Takuro; Harjo, S.; Zhang, K.*; Zhang, Z. D.*; Li, B.*

Applied Physics Letters, 123(1), p.011903_1 - 011903_6, 2023/07

https://doi.org/10.1063/5.0158607

Work function lowering of LaB by monolayer hexagonal boron nitride coating for improved photo- and thermionic-cathodes

Yamaguchi, Hisato*; Yusa, Ryunosuke*; Wang, G.*; Pettes, M. T.*; Liu, F.*; Tsuda, Yasutaka; Yoshigoe, Akitaka; Abukawa, Tadashi*; Moody, N. A.*; Ogawa, Shuichi*

Applied Physics Letters, 122(14), p.141901_1 - 141901_7, 2023/04

https://doi.org/10.1063/5.0142591

A lowering of work function for LaB by monolayer hexagonal BN coating is reported. Photoemission electron microcopy (PEEM) and thermionic emission electron microscopy (TEEM) both revealed that the hBN coated region of a LaB(100) single crystal has lower work function compared to the bare (i.e., non-coated) and graphene coated regions. A larger decrease of work function for the hBN coated LaB(100) compared to graphene coated LaB(100) was qualitatively supported by our density functional theory (DFT) calculations. Adding an oxide layer in the calculations improved consistency between the calculation and experimental results. We followed up our calculations with synchrotron-radiation X-ray photoelectron spectroscopy (SR-XPS) and confirmed the presence of an oxide layer on our LaB.

Thermal stability of non-collinear antiferromagnetic MnSn nanodot

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

Applied Physics Letters, 122(12), p.122404_1 - 122404_5, 2023/03

https://doi.org/10.1063/5.0135709

Spin motive force induced by parametric excitation

Hoshi, Kojiro*; Hioki, Tomosato*; Saito, Eiji

Applied Physics Letters, 121(21), p.212404_1 - 212404_6, 2022/11

https://doi.org/10.1063/5.0129466

Electrical properties and energy band alignment of SiO/GaN metal-oxide-semiconductor structures fabricated on N-polar GaN(000) substrates

Mizobata, Hidetoshi*; Tomigahara, Kazuki*; Nozaki, Mikito*; Kobayashi, Takuma*; Yoshigoe, Akitaka; Hosoi, Takuji*; Shimura, Takayoshi*; Watanabe, Heiji*

Applied Physics Letters, 121(6), p.062104_1 - 062104_6, 2022/08

https://doi.org/10.1063/5.0095468

The interface properties and energy band alignment of SiO/GaN metal-oxide-semiconductor (MOS) structures fabricated on N-polar GaN(000) substrates were investigated by electrical measurements and synchrotron-radiation X-ray photoelectron spectroscopy. They were then compared with those of SiO/GaN MOS structures on Ga-polar GaN(0001). Although the SiO/GaN(000) structure was found to be more thermally unstable than that on the GaN(0001) substrate, excellent electrical properties were obtained for the SiO/GaN(000) structure by optimizing conditions for post-deposition annealing. However, the conduction band offset for SiO/GaN(000) was smaller than that for SiO/GaN(0001), leading to increased gate leakage current. Therefore, caution is needed when using N-polar GaN(000) substrates for MOS device fabrication.

Temperature dependence of positron annihilation lifetime in near-surface and bulk of room-temperature ionic liquid observed by a slow positron beam

Hirade, Tetsuya; Michishio, Koji*; Kobayashi, Yoshinori*; Oshima, Nagayasu*

Chemical Physics Letters, 795, p.139507_1 - 139507_4, 2022/05

https://doi.org/10.1016/j.cplett.2022.139507

We obtained the temperature dependence up to 150C of the triplet positronium (-Ps) lifetime in N,N,N-Trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide (TMPA-TFSI) by the vertical slow positron beamline installed at AIST. Positrons penetrate into the liquid surface of TMPA-TFSI with the positron energies of 2 keV and 12 keV to investigate at the near-surface and the balk. The surface structure was visible at 150C, 120C above the melting temperature. The -Ps lifetime became shorter at higher temperatures for both positron energies. Similar temperature dependence had appeared just in water as the result of the reaction of -Ps and radiolysis products such as the OH radicals. The temperature dependence observed for TMPA-TFSI suggested that the chemical reaction of -Ps occurred.

Fabrication of (Bi)(BiTe) superlattice films by Te desorption from a pristine BiTe film

Kusaka, Shotaro*; Sasaki, Taisuke*; Sumida, Kazuki; Ichinokura, Satoru*; Ideta, Shinichiro*; Tanaka, Kiyohisa*; Hono, Kazuhiro*; Hirahara, Toru*

Applied Physics Letters, 120(17), p.173102_1 - 173102_5, 2022/04

https://doi.org/10.1063/5.0090207

Hydration structures of barium ions; molecular dynamics simulations using the SCAN meta-GGA density functional and EXAFS spectroscopy studies

Yamaguchi, Akiko; Kobayashi, Keita; Takahashi, Yoshio*; Machida, Masahiko; Okumura, Masahiko

Chemical Physics Letters, 780, p.138945_1 - 138945_5, 2021/10

https://doi.org/10.1016/j.cplett.2021.138945

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