It houses the Taiwan Light Source (TLS) and Taiwan Photon Source (TPS). Additionally, the NSRRC also operates two beamlines at SPring-8 in Japan and the Sika neutron scattering instrument at the OPAL research reactor in Australia..
The electrochemical reduction of CO2 (CO2RR) to formic acid (HCOOH) is both economically viable and technically promising for industrial applications. However, current catalysts for HCOOH production exhibit substantial overpotentials to achieve industrial production rates. This limitation stems from the relatively low activity for solvent–water activation of high HCOOH-selective catalysts, e.g., Bi and Sn, which in turn leads to a high energy barrier for the hydrogenation of CO2-to-*HCOO intermediates. Here, we report the exclusive CO2-to-formate conversion on Zn, a well-known CO-selective catalyst with moderate hydrogen evolution activity, via atomic indium oxide domain (In1O6) functionalization. The catalyst demonstrates Faradaic efficiencies for HCOOH exceeding 90
Altermagnets have attracted significant interest recently. Through the altermagnetic spin-splitting effect (ASSE), a longitudinal spin-polarized or a transverse pure spin current can be generated upon charge current injection. The ASSE is a key experimental feature for altermagnets but is often mixed with the spin Hall effect (SHE). Here, we present a comprehensive study of spin-to-charge conversion in epitaxial ruthenium dioxide (RuO2) thin films using the ferromagnetic insulator yttrium iron garnet (YIG) as the spin current source. We conclusively show the absence of the ASSE in RuO2 films grown with three different crystal orientations. Instead, we attribute the spin-to-charge conversion signals solely to the SHE. Moreover, we reveal a negative spin Hall angle in RuO2 when it is adjacent to YIG, which reverses the sign when interfaced with Py. Our study provides crucial insights into the recent arguments on RuO2 and advances the understanding of spin-to-charge conversion in low-symmetry materials.
Atomic-scale modulation of crystalline ordering in heterogeneous catalysts offers a critical pathway to enhance reaction kinetics, yet fundamental understanding of how their dynamic structural evolution governs active-site stability remains elusive. Here, we decode these effects by precisely engineering crystallographic gradients from ordered to disordered states, within octahedral building blocks (isolated octahedra [MO6] or dimer [M2O9]) of perovskite oxides Ba3MxRu2-xO9 (M = Fe, Co). This atomic-level control induces systematic shifts in d/p-band centers and optimizes charge distribution architectures within active regions. Crucially, the highly disordered Ba3FeRu2O9 achieves exceptional stability via a self-sacrificial reduction of iron, which generates a built-in electric field (BEF). The BEF promotes optimal adsorption/desorption kinetics of OH*/H* intermediates for the hydrogen evolution reaction (HER). Consequently, Ba3FeRu2O9 delivers benchmark alkaline HER performance, achieving an overpotential of just 24 mV at 10 mA cm-2 and demonstrating operational stability exceeding 600 h. Our results reveal that structural reorganization, enabled by atomic-level ordering modulation, is critical for establishing dynamic structure-performance frameworks to guide advanced catalyst design.
The recent discovery of high-temperature superconductivity in hole-doped SmNiO2, exhibiting the record-high transition temperature Tc among infinite-layer (IL) nickelates, has opened a new avenue for exploring design principles of superconductivity. Experimentally determining the electronic structure and magnetic interactions in this new system is crucial to elucidating the mechanism behind the enhanced superconductivity. Here, we report a Ni L-edge resonant inelastic x-ray scattering (RIXS) study of superconducting Sm-based IL nickelate thin films Sm1-x-yEuxCayNiO2 (SECNO). Dispersive paramagnonic excitations are observed in both optimally and overdoped SECNO samples, supporting a spin-fluctuation-mediated pairing scenario. However, despite the two-fold enhancement of Tc in the Sm-based nickelates compared to their Pr-based counterparts, the effective exchange coupling strength is reduced by approximately 20%. This behavior contrasts with hole-doped cuprates, where magnetic interactions correlate positively with Tc, highlighting essential differences in their superconducting mechanisms.
High-T_{c} superconductivity has recently been discovered in Ruddlesden-Popper (RP)-phase nickelates under pressure, where the low-energy electronic structure is dominated by Ni d_{x^{2}−y^{2}} and d_{z^{2}} orbitals. However, the respective roles of these orbitals in superconductivity remain unclear. Here, by combining x-ray absorption, electron energy loss spectroscopy, and density functional theory calculations on La_{4}Ni_{3}O_{10} single crystals, we identify ligand holes in the p_{x,y} orbitals of planar oxygen and the p_{z} orbitals of apical oxygen, which hybridize with the Ni d_{x^{2}−y^{2}} and d_{z^{2}} orbitals, respectively. These ligand holes enable orbital-selective O K-edge resonant inelastic x-ray scattering (RIXS) study, which reveals that d_{x^{2}−y^{2}} states dominate the low-energy charge excitations and are more itinerant. We also observe an ∼0.1eV bimagnon through RIXS and Raman spectroscopy. Our results reveal distinct contributions of Ni d_{x^{2}−y^{2}} and d_{z^{2}} orbitals to the electronic and magnetic structure and provide direct experimental insights to understand the RP-phase nickelate superconductors.
