Altermagnets combine the vanishing net magnetization of antiferromagnets with momentum-dependent spin splitting. Magnon band splitting provides a direct probe of altermagnetic order and may enable chirality-selective magnon transport, yet the momentum-space symmetry of this splitting has not been determined quantitatively. Here we use inelastic neutron scattering to map the momentum dependence of altermagnetic magnon splitting in hematite (α-Fe_2O_3). The splitting vanishes along nodal directions and reaches maxima off the nodes, revealing the g-wave symmetry of the altermagnetic order parameter. These results agree with linear spin-wave theory calculations based on the altermagnetic model, which further identify the nondegenerate branches as magnons of opposite chirality and trace the splitting to symmetry-inequivalent long-range exchange interactions. Our results provide the first quantitative determination of the momentum-space symmetry of altermagnetic chiral magnons. These findings, together with hematite's high magnetic ordering temperature and low magnon damping, establish it as a promising platform for low-dissipation, symmetry-selective magnonic applications.

The Rongzai Era (RZera) software was previously introduced as a user friendly solution for total scattering data reduction at the China Spallation Neutron Source (CSNS), capable of processing both diffraction and pair distribution function (PDF) data. Building upon the subsequent development of new time-focusing method for the high-resolution diffractometer (TREND) and a novel software package for the small-angle neutron scattering (SANS) instrument, we present RZera 3.0. This major upgrade introduces a unified, modular dataflow architecture that has been systematically deployed across multiple powder diffractometers at CSNS for both online and offline software. A key innovation is the modular workflow, which allows users to execute, inspect, and optionally bypass individual correction steps, providing transparency and control compared to the original "one-click" paradigm. For PDF analysis, RZera 3.0 integrates the Hermite function fitting method to effectively remove instrumental resolution effects. For diffraction data reduction, an automated scale factor calculation has been developed to optimize background subtraction. Furthermore, the platform’s scope now includes online reduction for the high-energy direct geometry inelastic spectrometer. This evolution transforms RZera from a single-instrument tool into a versatile, efficient, and centralized data reduction platform that serves a significant portion of the CSNS user community.

The Cold-Neutron Inelastic Spectrometer (CNIS) is a direct-geometry, time-of-flight instrument designed for the China Spallation Neutron Source and optimized to probe low-energy lattice and magnetic excitations. The instrument integrates a long flight path with bent supermirror guides and an elliptical-focusing geometry to suppress high-energy background while improving cold-neutron delivery to the sample. A flexible multi-disk chopper suite provides pulse shaping, band selection, and monochromatization, enabling multi-Ei operation. Modular features, including an interchangeable high-focusing guide insert, radial collimation, and a vacuum "airbox" for simplified sample-environment integration, enhance signal-to-noise and operational versatility. Through combined flight-path and chopper optimization, CNIS achieves excellent routine-mode energy resolution and can reach approximately ∼1% in a dedicated high-resolution configuration. CNIS is planned to commence user operation in 2029, offering a highly flexible platform for cold-neutron inelastic scattering studies.

Neutron scattering is a powerful technique for investigating crystal structure, magnetic structure and microscopic dynamical properties by analyzing the energy and momentum transfers between incident neutrons and the sample. This paper presents the key design specifications and technical parameters of two advanced neutron inelastic scattering instruments, developed over six years: XINGZHI cold neutron triple-axis spectrometer with polarization analysis, and BOYA multiplexing cold neutron spectrometer.u201D For u201CXINGZHI,u201D the implementation and test results of the S-bender supermirror neutron polarizer are presented, which marks the first use of S-benders both before and after the sample position on a triple-axis spectrometer for polarized neutron experiments. Meanwhile, u201CBOYAu201D features an innovative crystal double-column Rowland focusing analyzer design that optimizes energy resolution and enhances signal intensity. This spectrometer can simultaneously map excitation spectra across 34 momentum transfers within a 119u00B0 scattering angle range. Each analyzer channel includes five fixed final energy levels, plus an elastic diffraction channel, achieving a detection efficiency two orders of magnitude higher than that of conventional triple-axis spectrometers. Finally, experimental studies and data analyses conducted using u201CXINGZHIu201D and u201CBOYAu201D will investigate applications in condensed matter physics, focusing on topics such as unconventional superconductors, quantum spin liquid candidates, multiferroic materials, and low-dimensional magnetic systems.

As a fundamental physical phenomenon, achieving and controlling a large anomalous Hall effect (AHE) is crucial for advancing the understanding of topological physics and for developing applied technologies in spintronics. The recently discovered topological Kagome metal AV_3Sb_5 (A = K, Rb, Cs)exhibits a significant AHE along with charge density wave (CDW) and superconductivity, providing an ideal platform to study the interactions between nontrivial band topology, CDW, and superconductivity. In this study, we systematically investigated the evolution of CDW, superconductivity, and AHE in electron (Mn)-doped Cs(V_1-xMn_x)_3Sb_5 single crystals. The experimental results show that electron doping rapidly suppresses superconductivity, while the CDW order remains relatively robust. Meanwhile, a significantly enhanced AHE, with a maximum anomalous Hall conductivity (AHC) of 25331 ^-1^-1 and an anomalous Hall angle of 6.66 relatively low doping level of x = 0.03. Based on the Tian-Ye-Jin (TYJ) scaling model, such a significant enhancement AHC is mainly dominated by the skew scattering. We speculated enhanced skew scattering between electrons and Mn originating from the strengthened spin-orbital coupling. Our finding provides important guidance for the design and development of transverse transport properties in topological Kagome materials.

Inelastic neutron scattering is a pivotal technique in materials science and physics research,revealing the microscopic dynamic properties of materials by observing the changes in energy and momentum of neutrons interacting with matter.This technique provides important information for quantitatively describing the phonon dispersion and magnetic excitation of materials.Inelastic neutron scattering spectrometers can be divided into triple-axis spectrometers and time-of-flight spectrometers,according to the method of selecting monochromatic neutrons.The former has high signal-to-noise ratio,flexibility,and precise tracking capabilities for specific measurement points,while the latter significantly improves experimental efficiency through various measures.The application of inelastic neutron scattering spectrometers is quite extensive,playing an indispensable role in advancing frontier scientific research in the study of mechanisms in various materials such as magnetism,superconductivity,thermoelectrics,and catalysis.The high-energy inelastic spectrometer at the China Spallation Neutron Source is the first time-of-flight neutron inelastic spectrometer in China,achieving high resolution and multi-energy coexistence with its innovative Fermi chopper design.Additionally,the number of available single neutron beams in the experiment of this facility has reached the international leading level.

Developing neutron spectrometers with higher counting efficiency has been an essential pursuit in neutron instrumentation. In this work, we present BOYA, a multiplexing cold neutron spectrometer designed and implemented at the China Advanced Research Reactor. Equipped with 34 angular analyzing channels spanning 119°, each containing 5 inelastic channels and 1 diffraction channel, BOYA enhances the measurement efficiency by two orders of magnitude over a traditional triple-axis spectrometer. To optimize both intensity and energy resolution, innovative double-column Rowland focusing analyzers have been developed. By filling the crystal gaps in the traditional Rowland focusing geometry, our design enhances the neutron beam coverage without introducing appreciable double-scattering. Our commissioning results on vanadium and MnWO4 have confirmed the success of the design, establishing BOYA as a successful multiplexing instrument for neutron spectroscopy.

As a fundamental physical phenomenon, achieving and controlling a large anomalous Hall effect (AHE) is crucial for advancing the understanding of topological physics and for developing applied technologies in spintronics. The recently discovered topological Kagome metal $A$V$_3$Sb$_5$ ($A =$ K, Rb, Cs)exhibits a significant AHE along with charge density wave (CDW) and superconductivity, providing an ideal platform to study the interactions between nontrivial band topology, CDW, and superconductivity. In this study, we systematically investigated the evolution of CDW, superconductivity, and AHE in electron (Mn)-doped Cs(V$_{1-x}$Mn$_x$)$_3$Sb$_5$ single crystals. The experimental results show that electron doping rapidly suppresses superconductivity, while the CDW order remains relatively robust. Meanwhile, a significantly enhanced AHE, with a maximum anomalous Hall conductivity (AHC) of ~25331 \Ohm ^{-1}\cm^{-1} and an anomalous Hall angle of 6.66% occurs at a relatively low doping level of $x = 0.03$. Based on the Tian-Ye-Jin (TYJ) scaling model, such a significant enhancement AHC is mainly dominated by the skew scattering. We speculated enhanced skew scattering between electrons and Mn originating from the strengthened spin-orbital coupling. Our finding provides important guidance for the design and development of transverse transport properties in topological Kagome materials.

The rare earth intermetallic system RAlX (R = rare earth elements, X = Si and Ge) is known to be a promising candidate of magnetic Weyl semimetal. Due to the complex interactions between the rare earth elements and surrounding atoms, as well as hybridization with itinerant electrons, this family likely possesses highly intriguing and novel magnetic structures and thus exhibits dynamic behaviors. We systematically probe polycrystalline samples of RAlSi (R = La, Ce, Pr, and Nd) combining inelastic neutron scattering (INS), heat capacity, and magnetic susceptibility measurements. The INS measurements identify well-resolved crystalline electric field (CEF) excitations at 19.2 and 24.9 meV in CeAlSi, at 5.4 meV in PrAlSi, and at 2.5 and 4.2 meV in NdAlSi. We analyzed the INS data using the corresponding CEF models and determined the CEF parameters and ground state wave functions of RAlSi (R = Ce, Pr, and Nd). Our results suggest strong single-ion anisotropy in their ground states: |+/- 3/2) (94.5%) in CeAlSi, |+/- 3) (99.2%) in PrAlSi, and |+/- 9/2) (76.2%) in NdAlSi. Notably, the weaker anisotropy and strong exchange interactions in NdAlSi promote competing magnetic orders and CEF splitting at low temperature, contrasting with the robust CEF levels in magnetic states of CeAlSi and PrAlSi.

Lead halide perovskites are renowned for their exceptional optoelectronic properties but face concerns over lead toxicity and stability, which drives the exploration of lead-free perovskites, with Cs2AgBiBr6 standing out as a benchmark alternative. Understanding the structural dynamics and thermal transport properties of Cs2AgBiBr6 is crucial but remains an outstanding challenge due to the complex atomic fluctuations. Here, through diffuse scattering experiments and simulations, we uncover the underlying dynamic local structure in Cs2AgBiBr6, showing a unique two-dimensional spatial correlation. The inelastic X-ray scattering experiments and simulations further confirm the strong anharmonicity and short phonon lifetimes in Cs2AgBiBr6. An ultralow thermal conductivity of ∼0.36 W m-1 K-1 was measured by the frequency-domain thermoreflectance technique, with abnormal weak temperature dependence (∼ T-0.7). These results offer new insights into the lattice dynamics of lead-free double perovskites and are critical to understanding the electron-phonon and phonon-phonon couplings for their applications such as optoelectronics.

The method of temperature measurement with neutron resonance absorption is a non-contact temperature measurement technique, which makes use of the excellent penetration characteristics of neutrons and the Doppler broadening of the neutron resonance absorption cross section to obtain the static and dynamic temperature parameters as well as the temperature distribution in a closed system. The height and width of resonance absorption peak various with object temperature. By appropriate calibration, the temperature would be obtained with measuring neutron resonance absorption. In this paper, the width of neutron resonance absorption of neutron cross section and neutron transmittance various with tungsten coating/foil temperature are investigated. Result shows that variation in the full width at half maximum (FWHM) of resonance peak with square root temperature and width foil thickness are linear. By measuring the FWHM of resonance peak and the thickness of foil, the temperature could be calculated. Based on the FWHM of resonance peak of neutron transmittance, the data library could be generated for remote temperature measuring technique.

The High energy Direct geometry spectrometer (HD) is a direct geometry time-of-flight chopper spectrometer currently under construction, and it will be the first inelastic neutron scattering instrument at the China Spallation Neutron Source. With its high neutron flux and a 160 degrees angular coverage of 3 m long position -sensitive 3He detectors, the spectrometer will mainly be used to probe inelastic signals of novel spin and lattice dynamics in condensed matters and functional materials. The HD spectrometer is equipped with three switchable Fermi slit packages providing monochromation for both thermal and epithermal neutrons from 10 meV to 1500 meV, as well as a high-resolution repetition-rate multiplication (RRM) mode using curved slits. A special feature as a strict single incident energy mode can be provided using the combination of specially designed disk choppers and Fermi choppers. The design of the HD spectrometer is discussed in details.

We have systematically studied physical properties of Ba ð Fe 0 . 97 Cr 0 . 03 Þ 2 ð As 1 − x P x Þ 2 , where superconductivity in BaFe 2 ð As 1 − x P x Þ 2 is fully suppressed by just 3% of Cr substitution of Fe. A quantum critical point is revealed at x ∼ 0 . 42 , where non-Fermi-liquid behaviors similar to those in BaFe 2 ð As 1 − x P x Þ 2 are observed. Neutron diffraction and inelastic neutron scattering measurements suggest that the quantum critical point is associated with the antiferromagnetic order, which is not of conventional spin-density-wave type as evidenced by the ω =T scaling of spin excitations. On the other hand, no divergence of low-temperature nematic susceptibility is observed when x is decreased to 0.42 from higher doping level, demonstrating that there are no nematic quantum critical fluctuations. Our results suggest that non-Fermi-liquid behaviors in iron-based superconductors can be solely resulted from the antiferromagnetic quantum critical fluctuations, which cast doubts on the role of nematic fluctuations played in the normal-state properties in iron-based superconductors.

The vanadium doping effects on the superconductivity and magnetism of iron pnictides are investigated in Ba(Fe0.92-xCo0.08Vx)(2)As-2 by transport, susceptibility, and neutron scattering measurements. The doping of magnetic impurity V causes a fast suppression of superconductivity with T-C reduced at a rate of approximately 7.4 K/1% V. On the other hand, for x >= 0.02, long-range C-type antiferromagnetic order is recovered upon V doping, in contrast to the x = 0 sample with no detectable magnetic order. The value of ordered magnetic moments of Ba(Fe0.92-xCo0.08Vx)(2)A(s)2 follows a domelike evolution versus doping concentration x. A possible Griffiths-type antiferromagnetic region of multiple coexisting phases in the phase diagram of Ba(Fe0.92-xCo0.08Vx)(2)As-2 is identified, in accordance with previous theoretical predictions based on the cooperative behavior of magnetic impurities and conduction electrons mediating the Ruderman-Kittel-Kasuya-Yosida interactions between them.

A new cold neutron triple axis spectrometer named Kunpeng at the China Mianyang Research Reactor (CMRR), Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics has been constructed and fully tested. It can be typically used to study magnetic excitations, spin and lattice dynamics in condensed matter physics. In this contribution we present its main features and the first experimental data to demonstrate its performance.

The vanadium doping effects on superconductivity and magnetism of iron pnictides are investigated in Ba(Fe_0.92-xCo_0.08V_x)_2As_2 by transport, susceptibility and neutron scattering measurements. The doping of magnetic impurity V causes a fast suppression of superconductivity with T_c reduced at a rate of 7.4 K/1%V. On the other hand, the long-range commensurate C-type antiferromagnetic order is recovered upon the V doping. The value of ordered magnetic moments of Ba(Fe_0.92-xCo_0.08V_x)_2As_2 follows a dome-like evolution versus doping concentration x. A possible Griffiths-type antiferromagnetic region of multiple coexisting phases in the phase diagram of Ba(Fe_0.92-xCo_0.08V_x)_2As_2 is identified, in accordance with previous theoretical predictions based on a cooperative behavior of the magnetic impurities and the conduction electrons mediating the Ruderman-Kittel-Kasuya-Yosida interactions between them.

We have systematically studied physical properties of Ba(Fe_{0.97}Cr_{0.03})_{2}(As_{1-x}P_{x})_{2}, where superconductivity in BaFe_{2}(As_{1-x}P_{x})_{2} is fully suppressed by just 3% of Cr substitution of Fe. A quantum critical point is revealed at x∼0.42, where non-Fermi-liquid behaviors similar to those in BaFe_{2}(As_{1-x}P_{x})_{2} are observed. Neutron diffraction and inelastic neutron scattering measurements suggest that the quantum critical point is associated with the antiferromagnetic order, which is not of conventional spin-density-wave type as evidenced by the ω/T scaling of spin excitations. On the other hand, no divergence of low-temperature nematic susceptibility is observed when x is decreased to 0.42 from higher doping level, demonstrating that there are no nematic quantum critical fluctuations. Our results suggest that non-Fermi-liquid behaviors in iron-based superconductors can be solely resulted from the antiferromagnetic quantum critical fluctuations, which cast doubts on the role of nematic fluctuations played in the normal-state properties in iron-based superconductors.

in BaðFe0.97Cr0.03Þ2ðAs1− xPxÞ2 Wenliang Zhang, Yuan Wei, Tao Xie, Zhaoyu Liu, Dongliang Gong, Xiaoyan Ma, Ding Hu, Petr Čermák, Astrid Schneidewind, Gregory Tucker, Siqin Meng, Zita Huesges, Zhilun Lu, Jianming Song, Wei Luo, Liangcai Xu, Zengwei Zhu, Xunqing Yin, Hai-Feng Li, Yi-feng Yang, Huiqian Luo, and Shiliang Li 1 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics,

固相微萃取(solid-phase microextraction,SPME)技术是基于采用涂有固定相的熔融石英纤维来吸附、富集样品中待测物质的高效样品前处理技术,已在食品、环境、生物、临床医学等分析领域得到广泛的应用.敞开式质谱(ambient mass spectrometry,AMS)可在大气压下直接完成对样品的离子化及质谱分析,其离子化方式有多种选择.近年来,研究人员通过SPME与AMS联用,最大限度地发挥了固相微萃取与敞开式质谱的优势,可有效解决食品分析中的部分难题.本文对近年来SPME-AMS联用技术的研究进展及在食品分析中的应用现状进行了综述,并提出了该技术在未来发展中需要解决的若干问题.

Sr2Cr3As2O2 is composed of alternating square-lattice CrO2 and Cr2As2 stacking layers, where CrO2 is isostructural to the CuO2 building-block of cuprate high-T-c superconductors and Cr(2)As(2 )to Fe2As2 of Fe-based superconductors. Current interest in this material is raised by theoretic prediction of possible superconductivity. In this neutron powder diffraction study, we discovered that magnetic moments of Cr(II) ions in the Cr(2)As(2 )sublattice develop a C-type antiferromagnetic structure below 590 K, and the moments of Cr(I) in the CrO2 sublattice form the La2CuO4 -like antiferromagnetic order below 291 K. The staggered magnetic moment 2.19(4) mu(B)/Cr(II) in the more itinerant Cr2As2 layer is smaller than 3.10(6) mu(B)/Cr(I) in the more localized CrO2 layer. Different from previous expectations, a spin-flop transition of the Cr(II) magnetic order observed at 291 K indicates a strong coupling between the CrO2 and Cr2As2 magnetic subsystems.