Assessing and tackling the barocaloric fatigue for applicable solid-state refrigeration

Xue, J.*; Huang, D.*; Hattori, Takanori; Li, L.*; Feng, Y.*; Wang, H.*; Fan, X.*; Yao, J.*; Wang, Y.*; Liu, Z.*; et al.

Applied Physics Letters, 128(20), p.201903_1 - 201903_8, 2026/05

https://doi.org/10.1063/5.0333322

The cycling fatigue and barocaloric response of NHI is directly assessed under loading-unloading cycles with stress up to 100,MPa, with the adiabatic temperature change () decaying from 15,K to approximately 0.8,K after 100 cycles. X-ray diffraction, Raman spectroscopy, and neutron diffraction concertedly reveal the existence of the residual high-pressure phase even after the first unloading, whose fraction is rapidly increased to 90% at the 100th cycle. A phenomenological model is developed to elucidate this fatigue behavior, and an excellent agreement with experimental data has been achieved. To relieve the intergranular stress and enhance the mobility of grains, we encapsulate the composite of NHI particles and silicone oil into a 3D-printed polymer shell. Such an architectural tailoring has markedly improved the cyclic stability of the barocaloric effect with rising to c.a. 4.6,K after 100 cycles. Our results establish a fundamental understanding of the barocaloric fatigue behavior and pave a feasible route to applicable barocaloric cooling technology.

Theory of electric reactance emerging from spin Hall effect

Araki, Yasufumi; Ieda, Junichi

Applied Physics Letters, 128(9), p.092406_1 - 092406_7, 2026/03

https://doi.org/10.1063/5.0308872

Selective resonance ionization of calcium odd isotopes with odd-even selection rules

Wells, S. R.*; Iwata, Yoshihiro; Miyabe, Masabumi; Hasegawa, Shuichi*

Applied Physics B, 132(3), p.32_1 - 32_8, 2026/02

https://doi.org/10.1007/s00340-026-08641-0

Odd-even isotope selectivity in calcium was investigated using a laser resonance ionization J:0-1-0 transition scheme, chosen so that angular momentum selection rules could be manipulated using linearly polarized light. Suppression of the abundant isotope Ca and selection of the rare isotope Ca was confirmed as a function of the linear polarization angle. A maximal separation coefficient value of was obtained.

Highly black material made from activated carbon

Kaneda, Miyu*; Enomoto, Takamasa*; Kobayashi, Hiroyuki*; Fukada, Yukimasa; Kano, Jun*; Aoyagi, Yumito*; Fujii, Tatsuo*; Ikeda, Naoshi*

Japanese Journal of Applied Physics, 65(2), p.028001_1 - 028001_4, 2026/01

https://doi.org/10.35848/1347-4065/ae3508

Low-reflectance black materials play an important role in optical and thermal devices. In this study, boron-doped carbon nanowalls (CNWs) with extremely low reflectance were successfully synthesized using an inexpensive and simple experimental arrangement. Analysis of the nanostructures and surface morphology of the CNWs revealed that boron doped CNWs had a higher wall density and lower graphitization than undoped CNWs. We discuss the mechanism of light absorption in terms of stray light effects originating from the nanostructures and the improved electrical conductivity owing to carrier doping. Boron doped CNWs are considered beneficial for the implementation of this ultra-black material.

Induction of large in-plane uniaxial magnetic anisotropy for Co-Fe-B-Pt thin films by magnetic field annealing

Yamazaki, Takumi*; Ishitani, Yugo*; Nakada, Katsuyuki*; Sasaki, Tomoyuki*; Endo, Yasushi*; Takanashi, Koki; Seki, Takeshi*

Journal of Applied Physics, 138(23), p.233905_1 - 233905_11, 2025/12

https://doi.org/10.1063/5.0300010

Fe contribution to the magnetic anisotropy of -ordered FePt thin films studied by angle-dependent X-ray magnetic circular dichroism

Shibata, Goro; Ikeda, Keisuke*; Takanashi, Koki; Fujimori, Atsushi*; 8 of others*

Applied Physics Letters, 127(14), p.142406_1 - 142406_6, 2025/10

https://doi.org/10.1063/5.0283193

Large magnetic Bragg peak enhancement by ultrasound injection on FeTiO

Shamoto, Shinichi; Shin, K.*; Akatsu, Mitsuhiro*; Imai, Masaki; Ueta, Daichi*; Yokoo, Tetsuya*; Nemoto, Yuichi*; Hassan, A. M. A.*; Chang, L.-J.*; Ieda, Junichi; et al.

Applied Physics Letters, 127(13), p.132403_1 - 132403_5, 2025/09

https://doi.org/10.1063/5.0273424

Local and electronic structures of BaTiO/KNbO nanocomposite particles

Yoneda, Yasuhiro; Kobayashi, Toru; Tsuji, Takuya; Shibata, Goro; Takeda, Yukiharu*; Saito, Yuji; Khanal, G. P.*; Fujii, Ichiro*; Ueno, Shintaro*; Sato, Yukio*; et al.

Japanese Journal of Applied Physics, 64(8), p.08SP07_1 - 08SP07_8, 2025/08

https://doi.org/10.35848/1347-4065/adf4f1

It has become possible to synthesize high-quality composite nanoparticles in which a different material is grown on the surface of nanoparticle crystals. To evaluate such nanostructures, it is effective to combine different evaluation methods at various scales. We performed various structural and electronic state evaluations of BaTiO/KNbO nanocomposite particles using synchrotron radiation. From the structural evaluation, it was confirmed that the nanocomposite particles have a core of 100 nm of BaTiO covered with 20 nm of KNbO. The O-K absorption edge spectrum of the outermost surface KNbO was different from that of the bulk and nanoparticles, and it was found that the chemical bonding state changes when KNbO is made into composite particles.

Nonlinear Seebeck effect in NiFe|Pt at room temperature

Hirata, Yuya*; Kikkawa, Takashi; Arisawa, Hiroki*; Saito, Eiji*

Applied Physics Letters, 126(25), p.252408_1 - 252408_5, 2025/06

https://doi.org/10.1063/5.0269578

Mechanism of magnetization enhancement at the Fe/LiF/MgO interface elucidated through the first-principles calculations of the interface structure

Sekikawa, Takuya; Takada, Kazuki*; Kai, Takeshi; Ono, Yoshiaki*

Journal of Applied Physics, 137(20), p.203901_1 - 203901_10, 2025/05

https://doi.org/10.1063/5.0260903

no abstracts in English