A Record-High Cryogenic Magnetocaloric Effect Discovered in EuCl Compound.

Adiabatic demagnetization refrigeration (ADR) based on the magnetocaloric effect (MCE) is a promising technique to achieve cryogenic temperature. However, magnetic entropy change (Δ), the driving force of ADR, remains far below theoretical -Δ = ln(2 + 1)/ for most magnetic refrigerants. Here, we report giant MCE in orthorhombic EuCl, where a ferromagnetic ground state with excellent single-ion behavior of Eu and free spins has been demonstrated by combining calculations with Brillouin function analysis and magnetic measurements.

Quantitative Identification of Dopant Occupation in Li-Rich Cathodes.

Elemental doping is widely used to improve the performance of cathode materials in lithium-ion batteries. However, macroscopic/statistical investigation on how doping sites are distributed in the material lattice, despite being a key prerequisite for understanding and manipulating the doping effect, has not been effectively established. Herein, to solve this predicament, a universal strategy is proposed to quantitatively identify the locations of Al and Mg dopants in lithium-rich layered oxides (LLOs).

Low pressure reversibly driving colossal barocaloric effect in two-dimensional vdW alkylammonium halides.

Plastic crystals as barocaloric materials exhibit the large entropy change rivalling freon, however, the limited pressure-sensitivity and large hysteresis of phase transition hinder the colossal barocaloric effect accomplished reversibly at low pressure. Here we report reversible colossal barocaloric effect at low pressure in two-dimensional van-der-Waals alkylammonium halides. Via introducing long carbon chains in ammonium halide plastic crystals, two-dimensional structure forms in (CH-(CH))NHX (X: halogen element) with weak interlayer van-der-Waals force, which dictates interlayer expansion as large as 13% and consequently volume change as much as 12% during phase transition.

Phase transitions associated with magnetic-field induced topological orbital momenta in a non-collinear antiferromagnet.

Resistivity measurements are widely exploited to uncover electronic excitations and phase transitions in metallic solids. While single crystals are preferably studied to explore crystalline anisotropies, these usually cancel out in polycrystalline materials. Here we show that in polycrystalline MnZnGeN with non-collinear antiferromagnetic order, changes in the diagonal and, rather unexpected, off-diagonal components of the resistivity tensor occur at low temperatures indicating subtle transitions between magnetic phases of different symmetry.

High-density, spontaneous magnetic biskyrmions induced by negative thermal expansion in ferrimagnets.

Magnetic skyrmions are topologically protected quasiparticles that are promising for applications in spintronics. However, the low stability of most magnetic skyrmions leads to either a narrow temperature range in which they can exist, a low density of skyrmions, or the need for an external magnetic field, which greatly limits their wide application. In this study, high-density, spontaneous magnetic biskyrmions existing within a wide temperature range and without the need for a magnetic field were formed in ferrimagnets owing to the existence of a negative thermal expansion of the lattice.

Diffusive excitonic bands from frustrated triangular sublattice in a singlet-ground-state system.

Magnetic order in most materials occurs when magnetic ions with finite moments arrange in a particular pattern below the ordering temperature. Intriguingly, if the crystal electric field (CEF) effect results in a spin-singlet ground state, a magnetic order can still occur due to the exchange interactions between neighboring ions admixing the excited CEF levels. The magnetic excitations in such a state are spin excitons generally dispersionless in reciprocal space.

Chemical order-disorder nanodomains in FePt bulk alloy.

Chemical ordering is a common phenomenon and highly correlated with the properties of solid materials. By means of the redistribution of atoms and chemical bonds, it invokes an effective lattice adjustment and tailors corresponding physical properties. To date, however, directly probing the 3D interfacial interactions of chemical ordering remains a big challenge.

Metal-organic frameworks for food contaminant adsorption and detection.

Metal-organic framework materials (MOFs) have been widely used in food contamination adsorption and detection due to their large specific surface area, specific pore structure and flexible post-modification. MOFs with specific pore size can be targeted for selective adsorption of some contaminants and can be used as pretreatment and pre-concentration steps to purify samples and enrich target analytes for food contamination detection to improve the detection efficiency. In addition, MOFs, as a new functional material, play an important role in developing new rapid detection methods that are simple, portable, inexpensive and with high sensitivity and accuracy.

Acute arsenic exposure exacerbates lipopolysaccharide-induced lung injury possibly by compromising the integrity of the lung epithelial barrier in rats.

Inhalation of large amounts of arsenic can damage the respiratory tract and may exacerbate the development of bacterial pneumonia, but the exact mechanism remains unclear. In this study, male Wistar rats were randomly divided into control, arsenic trioxide (16.0 μg/kg ATO), lipopolysaccharide (0.

Proliferating Stem Cells are Acutely Affected by DNA Damage Induced by Sulfur Mustard.

Sulfur mustard (SM), a chemical warfare agent, can form adducts with DNA, RNA, and proteins. Reactions with DNA lead to the formation of both DNA monoadducts and interstrand cross-links, resulting in DNA damage, and is an important component of SM toxicity. Our previous studies indicated that dividing cells such as hematopoietic stem cells and intestinal villi stem cells seemed to have increased sensitivity to SM.

Magnetic phase diagram of the solid solution LaMn(GeSi) (0 ≤ x ≤ 1) unraveled by powder neutron diffraction.

The structural and magnetic properties of the ThCrSi-type solid solution LaMn(GeSi) (x = 0.0 to 1.0) have been investigated employing a combination of X-ray diffraction, magnetization and neutron diffraction measurements, which allowed establishing a magnetic composition-temperature phase diagram.

Elastic Lattice Enabling Reversible Tetrahedral Li Storage Sites in a High-Capacity Manganese Oxide Cathode.

The key to breaking through the capacity limitation imposed by intercalation chemistry lies in the ability to harness more active sites that can reversibly accommodate more ions (e.g., Li ) and electrons within a finite space.

Ultrawide Temperature Range Super-Invar Behavior of R_{2}(Fe,Co)_{17} Materials (R = Rare Earth).

Super Invar (SIV), i.e., zero thermal expansion of metallic materials underpinned by magnetic ordering, is of great practical merit for a wide range of high precision engineering.

Correlation of Tunable CoSi Tetrahedron with the Superconducting Properties of LaCoSi.

It is known that as the FeAs tetrahedron in the Fe-based superconductor is close to the regular tetrahedron, critical temperature () can be greatly increased. Recently, a Co-based superconductor of LaCoSi (4 K) with "111" structure was found. In this work, we improve the of LaCoSi through structural regulation.

Structural, magnetic, and electronic evolution of the spin-ladder system BaFeS Se with isoelectronic substitution.

We report experimental studies of a series of BaFeS Se (0 ⩽ ⩽ 3) single crystals and powder specimens using x-ray diffraction, neutron-diffraction, muon-spin-relaxation, and electrical transport measurements. A structural transformation from (BaFeS) to (BaFeSe) was identified around = 0.7 - 1.

A Distinct Spin Structure and Giant Baromagnetic Effect in MnNiGe Compounds with Fe-Doping.

Spin structure of a magnetic system results from the competition of various exchange couplings. Pressure-driven spin structure evolution, through altering interatomic distance, and hence, electronic structure produces baromagnetic effect (BME), which has potential applications in sensor/actuator field. Here, we report a new spin structure(CyS-AFM) with antiferromagnetic(AFM) nature in Fe-doped MnFeNiGe.

Superconductivity in Co-Layered LaCoSi.

It is known that few Co-based superconducting compounds have been found compared with their Fe- or Ni-based counterparts. In this study, we have found superconductivity of 4 K in the LaCoSi compound for the first time. The combined analysis of neutron and synchrotron X-ray powder diffractions reveals that LaCoSi exhibits an isostructure with the known Fe-based LiFeAs superconductor, which is the first "111" Co-based superconductor.

A combinatory ferroelectric compound bridging simple ABO and A-site-ordered quadruple perovskite.

The simple ABO and A-site-ordered AA'BO perovskites represent two types of classical perovskite functional materials. There are well-known simple perovskites with ferroelectric properties, while there is still no report of ferroelectricity due to symmetry breaking transition in A-site-ordered quadruple perovskites. Here we report the high pressure synthesis of an A-site-ordered perovskite PbHgTiO, the only known quadruple perovskite that transforms from high-temperature centrosymmetric paraelectric phase to low-temperature non-centrosymmetric ferroelectric phase.

Effect of HO Molecules on Thermal Expansion of TiCo(CN).

Understanding the role of guest molecules in the lattice void of open-framework structures is vital for tailoring thermal expansion. Here, we take a new negative thermal expansion (NTE) compound, TiCo(CN), as a case study from the local structure perspective to investigate the effect of HO molecules on thermal expansion. The in situ synchrotron X-ray diffraction results showed that the as-prepared TiCo(CN)·2HO has near-zero thermal expansion behavior (100-300 K), while TiCo(CN) without water in the lattice void exhibits a linear NTE (α = -4.

Large nonlinear optical effect in tungsten bronze structures via Li/Na cross-substitutions.

By a simple cross-substitution of A-site Li/Na in tetragonal tungsten bronze (TTB) structures, we successfully synthesized a new niobate compound, Pb2.15(Li0.25Na0.

Giant Topological Hall Effect and Superstable Spontaneous Skyrmions below 330 K in a Centrosymmetric Complex Noncollinear Ferromagnet NdMnGe.

Skyrmions with topologically nontrivial spin textures are promising information carriers in next-generation ultralow power consumption and high-density spintronic devices. To promote their further development and utilization, the search for new room temperature skyrmion-hosting materials is crucial. Considering that most of the previous skyrmion-hosting materials are noncollinear magnets, here, the detection of the topological Hall effect (THE) and the discovery of skyrmions at room temperature are first reported in a centrosymmetric complex noncollinear ferromagnet NdMnGe.

Strong Second Harmonic Generation in a Tungsten Bronze Oxide by Enhancing Local Structural Distortion.

To discover the nonlinear optical (NLO) materials with strong second harmonic generation (SHG), the design of NLO-active molecular units with large polarization is considered as a common strategy. Herein, we propose that the local structural distortion induced with vacancies, apart from the NLO-active units, can be employed to improve the NLO effect in solids as well. Accordingly, a new tungsten bronze (TB) oxide, Pb(PbLi□)NbO (□ representing vacancies), is successfully designed and prepared, which exhibits a strong SHG response of 39 times that of KHPO.

Unprecedented lattice volume expansion on doping stereochemically active Pb into uniaxially strained structure of CaBaPbZnGaO.

Lone pair cations like Pb are extensively utilized to modify and tune physical properties, such as nonlinear optical property and ferroelectricity, of some specific structures owing to their preference to adopt a local distorted coordination environment. Here we report that the incorporation of Pb into the polar "114"-type structure of CaBaZnGaO leads to an unexpected cell volume expansion of CaBaPbZnGaO (0 ≤ x ≤ 1), which is a unique structural phenomenon in solid state chemistry. Structure refinements against neutron diffraction and total scattering data and theoretical calculations demonstrate that the unusual evolution of the unit cell for CaBaPbZnGaO is due to the combination of the high stereochemical activity of Pb with the extremely strained [ZnGaO] framework along the c-axis.

Transforming Thermal Expansion from Positive to Negative: The Case of Cubic Magnetic Compounds of (Zr,Nb)Fe.

Negative thermal expansion (NTE) is an intriguing property for not only fundamental studies but also technological applications. However, few NTE materials are available compared with the huge amount of positive thermal expansion materials. The discovery of new NTE materials remains challenging.

Strong Negative Thermal Expansion in a Low-Cost and Facile Oxide of CuPO.

Negative thermal expansion (NTE) behaviors have been observed in various types of compounds. The achievement in the merits of promising low-cost and facile NTE oxides remains challenging. In the present work, a simple and low-cost CuPO has been found to exhibit the strongest NTE among the oxides (α ∼ -27.