Award type：Award from international society, conference, symposium, etc. 

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Nature Materials  

Advances in electrochemical devices have been primarily driven by the discovery and development of electrolyte materials. Yet the development of high-performance and chemically stable proton-conducting oxide electrolytes remains a challenge due to proton trapping and the resulting trade-offs between ionic carrier concentration and conductivity in doped oxides. Here we demonstrate that cubic perovskite oxides with heavy Sc doping can overcome these limitations. BaSn<inf>0.3</inf>Sc<inf>0.7</inf>O<inf>3–δ</inf> and BaTi<inf>0.2</inf>Sc<inf>0.8</inf>O<inf>3–δ</inf> are found to exceed the technological threshold of a total proton conductivity of 0.01 S cm⁻¹ for fuel cell electrolytes at 300 °C. The structural stability of BaSn<inf>0.3</inf>Sc<inf>0.7</inf>O<inf>3–δ</inf> is further validated under harsh chemical and fuel cell conditions. Molecular dynamics simulations using a machine learning force field illustrate rapid proton diffusion pathways along the ScO<inf>6</inf> octahedral network, effectively mitigating proton trapping, while protons are preferentially associated with Sc. Lattice softness is proposed as a primary design descriptor for increasing Sc content in perovskite oxides and developing high-performance electrolytes for electrochemical devices.

DOI： 10.1038/s41563-025-02311-w

Web of Science

Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：APL Materials  

Skyrmions, topologically protected quasiparticles, exhibit novel physical properties, such as the topological Hall effect and emergent electromagnetic dynamics, making them highly promising for spintronic applications. Their small size combined with fast transport at low power makes them attractive candidates for next-generation information carrier. However, these advantages cannot currently be realized simultaneously. One potential solution involves enhancing the spin-orbit torque (SOT) transferred from the heavy metal Pt layer to the magnetic layer. Here, we control the SOT efficiency by inserting an ultrathin layer between Pt and Co, as prior studies suggest that such an insertion layer can increase the spin-mixing conductance, thereby modulating the SOT efficiency. However, the insertion layer may also reduce the interfacial Dzyaloshinskii-Moriya interaction, a key factor in stabilizing skyrmions. In this work, we evaluated the SOT efficiency and skyrmion stability for two samples, the Pt/Co/Ni/Pt and Pt/Gd/Co/Ni/Pt systems, using Lorentz transmission electron microscopy. No significant difference was observed between the two samples, indicating that the SOT efficiency remained unaffected by the Gd insertion, and skyrmions formed in both cases.

DOI： 10.1063/5.0294523

Web of Science

Scopus

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Microscopy  

The precision in electron holography studies on electrostatic and magnetic fields depends on the image quality of an electron hologram. Enhancing the image quality of electron holograms is essential for the comprehensive analysis of weak electromagnetic fields; however, extended electron beam irradiation can lead to undesirable radiation damage and contamination. Recent studies have demonstrated that noise reduction using the wavelet hidden Markov model (WHMM) can improve the precision of phase analysis for limited thin-foiled crystals. In this study, we examine the effects of WHMM-based denoising on the electron holography data of weakly charged nanoparticles collected under low-electron-dose conditions. The results indicate that effective noise reduction with the WHMM allows for a reduction in the magnitude of the electron dose by approximately half relative to data collection without WHMM denoising, while maintaining the same level of charge determination precision: less than one elementary charge. Notably, at a low electron dose of 0.40 e⁻/pixel, WHMM denoising enables the clear visualization of a weak stray electric field outside a charged latex sphere. This method offers significant advantages for electron holography studies of electron-beam-sensitive materials requiring minimal time for electron exposure.

DOI： 10.1093/jmicro/dfaf007

Web of Science

Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Materials and Design  

Magnetic hysteresis properties in Fe/Si multilayers have been studied as a function of the B<inf>4</inf>C content to control magnetization amplitude, coercivity, and hysteresis tilt, properties that are beneficial to tune for advancing applications in e.g. data storage, spintronics, and sensors. With an ion-assisted magnetron sputtering technique, 35 distinct thin film multilayer samples were prepared and their magnetic and structural properties were characterized by vibrating sample magnetometry, X-ray photoelectron spectroscopy, near edge X-ray absorption fine structure spectroscopy, and X-ray and neutron scattering methods. Key findings indicate that adding B<inf>4</inf>C lowers the coercivity and can decrease the saturation magnetization, demonstrating the tunability of magnetic responses based on composition. For samples with Λ=30Å periodicity, 10–15 % of B<inf>4</inf>C addition produces antiferromagnetically (AF) coupled multilayers, and such AF coupling strength increases with the B<inf>4</inf>C content. Our findings reveal that B atoms do not chemically bind within the Fe atoms but instead occupy interstitial positions, disrupting medium- to long-range crystallinity thereby inducing the amorphization. Thereon, the observed effects on magnetic properties are directly attributed to this amorphization process caused by the presence of B<inf>4</inf>C. The demonstrated ability to finely adjust magnetic properties by varying the B<inf>4</inf>C content offers a promising approach to overcome challenges in magnetic device performance and efficiency.

DOI： 10.1016/j.matdes.2025.114387

Web of Science

Scopus

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Applied Microscopy  

In this study, we investigate the effectiveness of noise reduction in electron holography, based on the wavelet hidden Markov model (WHMM), which allows the reasonable separation of weak signals from noise. Electron holography observations from a Nd<inf>2</inf>Fe<inf>14</inf>B thin foil showed that the noise reduction method suppressed artificial phase discontinuities generated by phase retrieval. From the peak signal-to-noise ratio, it was seen that the impact of denoising was significant for observations with a narrow spacing of interference fringes, which is a key parameter for the spatial resolution of electron holography. These results provide essential information for improving the precision of electron holography studies.

DOI： 10.1186/s42649-024-00097-w

Scopus

PubMed

Language：English   Presentation type：Poster presentation  

Type：Scientific advice/Review